A rattle bag of reporting today as we wrap up the week. The big story has been insurance within the Yard for sea trials and the first year of voyaging. There has also been progress with commissioning systems. Finally, as we are temporarily in the USA, I decided to make the young boys in my family a model boat to glean their early interest. As we age, smarts are generally replaced by native cunning! Locating Marine Insurance Proves Problematic Firstly, we start with the sometimes sticky subject of insurance. It is tempting to rely on cognoscente dissonance when building a yacht in the belief that everything will be alright in the end. Certainly, you can help that strategy by not being a US Citizen and, secondly, not registering her under the US Flag. Both will cause you a great deal of difficulty in one way or another, especially as the value of the hull increases, as is our case. Add to that the insurance companies invariably ask for experience owning vessels of similar size or, at a minimum, their operation, and the whole issue becomes, in its way, a self-defeating pursuit. Believe me when I state that this is a challenging task. We initially obtained a good quotation from Pantaenius and relied on that going forward. In the interim, they stopped underwriting anything related to the USA; we can blame a mixture of hurricane claims and litigious proclivity for that one. Back to the drawing board, we reached out to a number of companies directly and also to two local specialist brokers. We have an acceptable offer, with terms as always, but given some effort, we will be insured by the Mediterranean and the North Atlantic, crossing to the USA through 2024. It is not much fun of a process, to be honest; this is the man who saved the day: Garrison Rudisill Maritime Insurance International 843.606.5270 Office ◆ 888.482.6844 Fax garrison@maritimeii.com ◆ maritimeii.com Naval Yachts have also had to obtain coverage under a refit policy to continue to progress sea trails past the year's end. Please don't ask me why, but that has caused a short delay. Happily, sea trails will begin again on Monday next week—more on that in a later blog. Systems commissioning Work on Vanguard has continued to progress commissioning systems and equipment. Webasto Blue Cool HVAC and potable hot water system is now functioning. Praxis Automation connected the Radar and began to calibrate the tank gauges. Wills Ridley steering has progressed, but we are waiting on a new interface board to connect rudder signals to the autopilot and DP system. No one knows why the original failed; it may be an installation error or static. Either way, once installed and working, we would not envisage a repeat of the issue. Outfitting the Tender for our Explorer Yacht Hebbeke Shipyard duly delivered our new waterjet tender for Vanguard. It's not a cheap exercise. However, to balance this, the final price came in very similar to buying a commercially available one of similar specification, and we have exactly what we want without the usual compromises. The Furuno navigation and associated instrumentation will be fitted in Antalya, Enclosed is the installations schematic to include sonar for safety in those less explored locations. Ballast Naval Yachts ran their stability calculations, having established a baseline from physical testing. This new work has indicated we will need some 2.5T of permanent ballast to maintain the required stability in the "arrival" trim. This will fit within the forepeak bilge, the twin aft skegs, and potentially under the cabin access, where we can also correct a permanent list due to the tender being on the port side. Lead was duly ordered and will be installed before undertaking official stability tests for UK MCA Category (0) designation. Chris Leigh-Jones Meanwhile, back home - Model Boat Antics Lastly, I started a project with some time to capture the imagination of two young boys in my US-based family. As a child, there were many model boats, some better than others, but it taught me the process. I have six weeks in the USA, so I set about a repeat. A really nice YouTube channel run by a father and son out of the West Coast offers some beautiful semi-scale sailboat plans. Off we went, building a facsimile pilot boat cutter. Six weeks is tight, but I think we can do it. Photos of progress are in the Blog below. Link to the Web Site HERE

Naval Yachts' Vanguard boat impresses in sea trials, exceeding estimated cruise speed and showcasing her wave-piercing design. A promising choice for boat enthusiasts and potential buyers. We have spent the last 6 weeks visiting friends and family; Naval Yachts have had a free run at completing Vanguard. This week, they crossed a significant milestone and began initial sea trials. A three-hour run after a long day but sufficient time to demonstrate a future promise. This is how it went. Initial sea trial results Sea state - calm Wind - light Load condition - Arrival but without permanent ballast. Trim - even keel Hull - 3 months in still seawater, probably mucky Note: The trim and rudder position remain to be optimized. Both engines were running at a similar speed. Stabilizers folded and inoperative. engines @1000 rpm @ 6,7 knots (also max speed for hybrid drive) engines @1500 rpm @ 9,8 knots engines @1680 rpm, and the speed was seen as 11.3 knots The predictions from Bruntons were remarkably accurate and better than for an equivalent fixed pitch propeller. More on this when additional detailed data is available inc one engine operation. The Vanguard's performance was impressive, aligning nicely with the predictions from Bruntons. However, it's worth noting that these predictions assumed a single engine running while we had two engines operating each at a lighter load. The Naval Architecture calculations indicated we should achieve this on a single engine, so that will be tested in the coming weeks. The typical direct correlation between shaft speed and load is removed as props are self-pitched. We still need to verify if the load display is calculated from engine speed or fuel rack position. Regardless, Vanguard exceeded our estimated cruise speed by 1.3kN at about 60% installed power load factor, with plenty of additional power to spare. It's safe to say that it was a successful day. Does she make waves? Wake at >11 knots. Swim platform remained dry, trim approximately even keel. The next test was to look at how Vanguard slipped through the water. Her sister ship, Mobius, was remarkably hydrodynamic in that regard. Those big white bow waves you see in magazines may look dramatic, but to my eye, they represent wasted fuel. Nothing is for free in this world. So Vanguard was operated at three speeds, rising through the load range to just over 9 knots before they ran out of time. See the video below. The bow wave was virtually non-existent. This wave-piercing design is an arrow! Some stern wake at higher speeds, but again, not much. Also, the stern has little to no tendency to bog down at higher speeds, with the swim platform staying dry throughout. Many displacement hulls will try to climb their bow wave when pushed hard, but not so with Vanguard, at least not so far. Video showing wake performance at circa 4.5, 8.4 and 9 knots. Note very little bow and side waves. Make waves = burn fuel! More data on fuel consumption to come when available. Ongoing Insurance Woes! Lastly - Insurance is proving to be an issue right now. US Nationals with a US-owned yacht is a troublesome mixture. Our go-to of Pantaenius no longer insures in the USA. I will blog when we have made more positive progress. Chris Leigh-Jones A few other things transpired this week but the above is the major news. Wishing everyone reading a very happy 2024. The crew and builders of Vanguard.

Our project Vanguard is near completion; holiday greetings for 2024! Some journeys are long, their continuations seemingly interminable, yet it is like these things that an end is inevitable. We are now at this point with Vanguard; Naval Yachts have moved to a higher gear, and we can see, smell, and almost taste the end of this project. It was a good end to a difficult year, and we look forward to the promise of 2024. We'd also like to wish our subscribers and readers a Merry Christmas and a very Happy New Year for 2024. I apologize for the delay in this update; Christmas got in the way! So, what has been completed in the two weeks since our last blog? John Deere Engines Praxis Automation sent their commissioning engineers to link up our systems, concentrating firstly on connecting the drives. This is the first time they have connected John Deer engines, so it took some effort to decode the J1939 CAN signals and secure the remaining hard-wired voltage and transducer input. That could have gone better, though I must credit their Commissioning Engineer with the skill and fortitude to see this through. Both engines are running; fuel systems are "air-free," hybrid drives and clutches function as intended, and twin disk gearboxes engage in both directions. Praxis and Wills Ridley steering We are moving on now to the steering system. We have three ways to steer: emergency manual hydraulic, Praxis Automation, and Wills Ridley direct control. All three are working though there remains an electrical niggle in switching between the latter two; the switch only works one way, though, that can be corrected in the New Year when the commissioning engineer arrives to check it out. MIMIC Diagrams and reporting systems So, with both engines and steering under control, we now have a functioning helm station. Further systems also came live at the helm. We installed BEP non-contact ultrasonic tank gauges throughout. These are currently working and reporting to the MIMIC systems. Calibration within Praxis systems uses tank-sounding data from the RHINO CAD design software: another job for the New Year. The fire alarm system and all access point limit switches are also live, as are the Navigation and Work Lights. Security cameras are functional, save for one, which is probably a wiring issue. The fuel transfer system is working, and we are circulating fuel between the two-day tanks via large Cummings Sea Flow filters to remove any construction debris picked up from within the tanks themselves. Any other business Internally, the cabins are almost complete, with the final floors going down as I write. 3000kg of lead ballast is on order, and the MCA Surveyor is on notice for our Category (0) survey in January. CE survey is already passed with a few small observations to be corrected. Initial sea trials are also now scheduled for early January. Planning has started for heading west, away from the Turkish coast, in February "inshallah." Chris Leigh-Jones We spent the Christmas holiday with family, part of which was on the Isle of White. I took the time to look at the western entrance to the Solent, past the Needles Light. The passage between the channel marker and the West Cardinal buoy was obvious from the cliffs. Wind Force 4/5 on the elevated cliff, maybe three at sea level, the tide was still generating some significant breakers; our way into Berthon International, Lymington, where we will have our first engine inspection and overhaul. Photo of our son Jeff and his partner Dawn plus the dog!

This year I'm 63, how did that happen? If I look back at 47 years in the shipping business, memorable moments have been when an old salt passed some snippet of hard earned knowledge. As others have tried innumerable times before, this is such an attempt. Maybe random format, unstructured or slightly jaded but hopefully useful. Have at it Folks! Design Owning a yacht is a significant investment in time and $$. Building one is doubly so. The fastest way afloat is to buy or refit an existing hull and only go down the build route if you cannot find what you need by any other means. Because of the expense, it is worthwhile to make a concerted effort to use every inch of available space. Waste nothing and think small. Installers can consume space with little thought; do not let them. Put effort into design, engineering, and planning early on in the build process and before construction starts in earnest. This is the principal opportunity to save cost and delay. Building to design Code is a minimum design case; adding hull strength and collision resistance at the build stage is much less expensive than the alternative. Lay out your electrical and instrumentation runs early, gathering them into logical terminations with good access. On larger hulls, use large-diameter fuel fill pipework for quick filling; remember that air breather pipes must not allow tanks to pressurize in the event of an overflow. Don't join breather pipes within the hull for convinience. Plan storage spaces early and defend them against lazy or imprudent installers. Crew and owner need to be allocated space for daily yacht operations; avoid surrendering it to subpar suppliers or designs. Plan space for extra mooring equipment and garbage storage in remote destinations. Monitor vessel weight closely; discuss weight allowances for different areas in advance. Consider material weights like marble, stone, or tiles, adding 15% for designer preferences. Interior designers may focus on aesthetics at the cost of practicality, sopem have never sailed at all! They also appreciate conveniently perpendicular walls and square corners. Test the ideas before approving them and watch for wasted space. Illustrations may need "interpretation" when they run up against the practicality of a build. Construction Pipes belong in floors where possible and never in deckheads. Wiring belongs in the deckhead or bulkhead and never bilge spaces. It's a simple but often ignored concept. Joints and connection boxes need to be accessible. Plan for excess cable trays and brackets. Welded cable brackets are preferable. Cable ties should not use glued saddles. Plan for larger cable trays than initially estimated and run spare cables on longer runs, especially for instrumentation & control through inaccessible areas. Segregate AC, DC, and data cables. A cable tie is not a pipe clamp; cables should never be clamped to pipes. Use "P Clips" for wires attached to machinery. Hoses & cables should each run true and not become intertwined in a run. Any through-hull penetration will need a vacuum break. Water generally flows downhill on this planet; water under hydrodynamic pressure flows any way it fancies. Seal the inner end of your rudder stocks. Hot water pipes can be small in diameter but ensure a permanent slow circulation to limit water use. Monitor weight during construction (preferably with load sensors). Maintain stability calculations as weights or added or removed. (This is often bottom of the yard's priority list.) Early on, plan for additional permanent ballast to preserve stability under "lightship" trim. Lead & epoxy is ballast, cement is for fishing boats. Anticipate penetrations by showing more than necessary in initial structural drawings. Cut them using CNC before construction, preventing the need for later additions. Use CNC to cut all limber holes per structural files to avoid oversight. Including them in the initial drawings saves time and prevents complications during construction. Order equipment as early as possible; late arrivals are costlier than expiring warranties. Suppliers often offer extended warranties for yet-to-be-installed equipment. Alternatively, order early, pay a deposit, and secure a fixed supply date and price. Read installation manuals for all equipment. Ensure Yard staff read them before installation (I could be tempted to swear at this point). As a matter of self-defense, prioritize installation by a qualified subcontractor, preferably one who supplied the equipment and is positioned to understand it best. Delay the insulation process until all welding, penetrations, and installations are complete. This prevents danger to onboard personnel and ensures a secure foundation for insulation. Avoid launching prematurely to satisfy a contractual date. It will only slow the completion process and frustrate everyone along the way. Inspection Use third-party inspection services to maintain quality when owner visits are limited. Avoid paper-based CE Certification services who do not visit during the build. It is often difficult to see your own mistakes. Consider a permanent owner representative on-site for a large build once the hull has been turned and outfitting begins. Consider access to installed equipment, pipework, and cables throughout construction. Facilitate easy removal and replacement with minimal labor by installing isolation valves and accessible features. Regularly update drawings and prevent old versions from circulating. Even without significant changes, update the issue to avoid confusion. Apply the KISS principle (Keep It Simple Stupid) to designs. Draw simple schematics for easy understanding and maintenance. Update all drawings to "as built" status before build completion. Contract Contracts should be clear, simple, and on point. Create a personal flow chart to ensure you understand how your contract works and respect its application. Penalty clauses for late delivery should be discussed early, and the effects of delays should be monitored. Their application should not be a matter of dispute. They will apply or will not and under what conditions should be clear in the contract. They should be used by an Owner to encourage on-time delivery and not as a means of cost saving. Mistakes happen; to err is human; blame is a mistake, and consequences are optional. In dealing with the Yard, remember that the goal is not to score minor contractural points. The plan is to go sailing, so make your decisions and allowances on that basis alone. Summary In summary, attention to detail in every aspect of yacht construction is a smart move. A yard and owner will be motivated by different information. The owner, however, will live with the end result, so allocate sufficient and timely attention. Lastly, consider attending Church occasionally; good luck has to be worked at and no good deed goes unpunished! Chris Leigh-Jones As a heads up, to help others de-risk the process, we are working on a Yacht Delivery, Voyage Crewing (Ice Pilot) and Build Superintendant offering for our readers who are building their own XPM or similar. That would include handholding during contract negotiations and training after the handover. More in a later blog early next year.

Vanguard is slowly coming alive at the dock in Antalya. Each day brings its minor successes, beginning to coalesce around a bigger story. We are away for a while now, seeing family and setting our businesses on course for the coming year. In the meantime, what has been happening with our build over the last week? Engineers from Praxis Automation attended Vanguard to begin activating our hybrid drives and DC power battery. Quite a nest of Ethernet and signal cables to first verify. Starting with the control and instrumentation systems, they powered up all 5 MFD displays so we could see how they responded. We have one screen at the helm dedicated to engineering functions and two for Navigation. The flybridge is one each. These MIMIC diagrams represent quite a lot of design work undertaken over a year ago. Our focus was more on reporting than control, with the latter remaining mostly manual to limit system complexity. A,"Get out of your seat and go have a look" sort of strategy. Three-phase shore power systems became life, then the navigation and deck light control systems. Tank sensors followed, and finally, we connected the DC power batteries and Energy Management systems to the hybrid drives. All remain incomplete, but we found time for hybrid drives to make their first few tentative turns in near silence! Two John Deere 4045 engines were next. Both started using the local engine room control systems independent of the main helm. Duplicate everything is our mantra. Just a quick start to ensure systems were operable and leak-fee. Integration with the data (J1939 CAN) and hard-wired drive line systems is now receiving focus that should have been applied sometime back but was lost between personal changes at the Yard. Better late than never, perhaps. The engine exhaust installation was also completed late this week and is now ready for sea trials. Wills Ridley and the emergency helm steering system were connected. The next stage is to fill the hydraulic tanks, bleed the system of remaining air, and then connect to the Wills Ridley and Praxis steering control system. That's a job for the upcoming week. The tender finally arrived from Hebbeke Shipyard in The Netherlands. She had already undergone local tests before shipping (see blog below), and the only remaining job is to install the Furuno TZ Touch navigation, GPS, and AIS instruments. 3000l of diesel fuel has been ordered from the bunker station in Antalya Free Trade Zone, sufficient for the initial sea trails and represents around 30% of her total capacity. Naval Yachts have also ordered the permanent ballast lead, which should arrive in a few weeks. See last week's Blog on Understanding Longitudinal Stability, which discusses the necessity for permanent lead ballast to improve stability under lightship arrival conditions, the proverbial cork in a barrel. Starlink and WIFI communications are now installed and working. Starlink still needs to be tested as it does not function in Turkey. As soon as we depart, it will come live. We recently also commissioned our Victron 220VAC and 24VDC electrical systems, including the remote monitoring portal, so that we can view system performance. I've mentioned previously getting our hands on a MIL Spec Visible and Infra-Red Wavelength Camera that we installed on the cabin roof. I'm not sure anyone is bothered about things behind us, but in front, definitely. A software driver was missing; it took some effort to track it down before the device burst into life. So far, testing has been limited to visible light conditions, and we have quickly investigated optical magnification and image stabilization. I'm sending a video of the results here; sorry about the quality. Optical magnification in the visible spectrum is an astounding 40X, so no more missing those bridge heights or Navigation Mark. This device is amazing for a paltry price relative to an excellent high-spec FLIR 400 or 500 series. That's the military for you. Two by 100m Kevlar shoreline reels were fixed to the rear stations. Flat rope will probably strum like hell in the wind (I've been warned), but that's a worry for another day. Our name, "Vanguard," was attached to the stern along with Jersey as the Port of Registry. HIN and maker plate were also fixed to the hull, and we have now officially registered under the Red Ensign; Vanguard is a real yacht! So that's it for this week. More to come as we approach our final weeks in Turkey and think about preparations to head West! Chris Leigh-Jones Out in the real world, our son, Jeff, has been busy delivering yachts around the NW European coast (more on this in a later Blog). Enclosed is a snapshot of his crew entering the Mersey shipping channel off the coast of North Wales en route to Liverpool. Winter sailing through a wind farm in a hail storm, no complaints, but probably not happy either!

The relationship between an Owner who commissions a project and a Yard who builds it will span several years. The best projects start and end with a basic understanding between the parties of how responsibilities fall and how each contributes to its success. Treated sensitively, this can be a fun experience, ignored, and contention will arise early on, always to remain. These notes are written from personal experience building our Explorer Yacht Vanguard, plus input from others in the business. There was room for improvement and we hope they are useful. Remember, if you have questions or wish to explore any aspect of your plans, we and the team at Artnautica remain an "email" or "WhatsApp" away. Best regards, Chris & Sebrina Leigh-Jones How the Process Unfolds XPM-78 is a semi-custom, proven explorer yacht concept. The form and layout design is produced by Artnautica, and the engineering and implementation are the responsibility of Naval Yachts. XPM designs have evolved considerably during the construction of the first two hulls. Within the confines of form and layout, the Yard will customize the Owner's specific requirements in each boat's technical specifications. This is the basis of your build. Each contract has 3 main annexes: Technical Specification, Preliminary Build Schedule, Payment Schedule (the Yard's cash flow) An Owner may tend to treat the design as their personal plaything and this will cause issues. We encourage including a significant amount of equipment or layout used on previous builds. Known quantities will reduce the uncertainty. The first hulls were built by sailors with marine experience in their respective fields, lean on it for less delay and a faster build. 100% detailing each document is challenging; it should be developed enough to provide information so the Yard and the Owner are clear on intent but remain willing to review. Under the guidance of the technical specifications, the engineering task can commence. Some engineering findings will affect one or all of these documents. Open and comprehensible communication on these occasions is paramount. It is tempting to design as you go along, in the field, on the spot. Avoid that temptation and confirm all you can reasonably achieve at an early stage. Going the "semi-custom" route will help considerably. We also strongly suggest that all "Engineering and Design" functions are completed BEFORE the build starts. It's the cheapest place to make changes; you will be thankful for this later. Naval Yachts are ISO 9001-certified; "If you can't measure it, you can't control it." Ensure that this process is adhered to and not used as window dressing. ISO9001 does not ensure quality; it should ensure consistency and traceability. The Yard will build the vessel using its staff and subcontractors. Problems will always occur during the build and will be addressed as they arise rather than holistically. Be ready to have those conversations in real time. Yacht building is an intricate business. It often needs to be more appreciated by Owners viewing a project remotely. Affirming new ideas is a common mistake in a Yard/Owner relationship, even when they may not be beneficial in the long run. So, be accepting of pushback when decisions are questioned. Remember also that Yard's are not sailors, they think "build ability" an owner should think "practicality". Changes in the layout or specifications after the initial stages can disturb workflows and increase costs significantly; direct labor is usually a minor part of the total impact. Yacht building is costly due to complexity and construction's one-off nature. Furnishings that would be affordable in a regular retail setting become exorbitant in a boatyard. Expect some interesting Change Orders if you go down that route. The build process must secure a reliable cash flow, if an owner defaults (it happens), finding a new project may take a year or more, leading to substantial losses, so a Yard must plan payments for work and profit to date. Yachts should only be moved to the water after completion or risk a considerable increase in labor hours and costs to complete. Premature launch also results in a knock-on effect on subsequent projects. Despite any delay, the monthly fixed expenses for the Yard continue. Express opinions but be careful not to take authority over what you cannot control, you take it, you own it. The Design Phase for your Yacht Project Maintain realistic expectations during the design phase. Define goals based on known, achievable parameters agreed with the Yard. Regularly review those goals. Limit exploring novel concepts to minimize the impact of unforeseen challenges. When new ideas are introduced by Owners, owners will need to retain responsibility for the learning curve of new equipment. Any and all changes will likely affect performance in some way, however subtle. Allocate safety factors to mass, budget, or center of gravity. Make sure they are tracked throughout the build. Yacht building is an imprecise science. Underestimate performance indicators, such as range or tank volumes, as adjustments will likely be necessary later on. Stay vigilant about potential side effects or issues that could arise during the design process. Consider alternative solutions in case of significant problems, and be prepared to adjust your course early on. Regularly revisit initial decisions and goals as the design evolves, avoid conforming to the status quo out of habit, and prioritize simplicity, sea comfort, and speed. An owner's idea of "acceptable" may differ greatly from the Yard's; regular and clear communication is important. The Build Phase Monitoring project progress can be challenging, but breaking the project into manageable parts with assigned labor hours and timelines can help track trends. If delays occur, ensure EARLY discussion of how to get the project back on track; do not just accept platitudes. Assumptions in the early design and cost projection stages should be revised as data changes. For instance, any enhancements that influence internal structure or weight should be monitored, and their influence accounted for. Change orders should be minimized to prevent schedule disruptions and maintain the owner's funds. They often result in domino effects on the production line. Above a de minimus figure, change orders will be implemented once the agreed payment is made. All changes requested should be documented with Change Orders, including the effect on delivery dates. Judging the quality of the build is tricky during construction, as protective covers conceal the finished work. Ultimately, you'll rely on the reputation of the team you're working with and feedback from previous clients. The desired level of fit and finish significantly influences cost and construction time. As perfection is approached, costs and time can escalate exponentially. Early system testing is essential to detect and rectify errors or malfunctions before leaving the Yard. It's also necessary to constantly update as-built data as the project evolves from the original design. Schedules are inevitably going to shift. Yards should resist the pressure to prematurely move the yacht for launching, as this only escalates costs and delays the project. If problems occur with the Yard, resist the temptation to order "STOP," pay what is due, and discuss the disagreement. The financial leverage tool should be used sparingly, or relationships will be permanently damaged. This is no place for a bully. The owner should only move aboard or bring personal items after completing sea trials. This can significantly hinder sea trial progress and completion. Owner visits are necessary, but they can also be disruptive. It is better to establish clear written guidelines about their timing and frequency at the contract stage. Enlisting an external surveyor for periodic inspections can safeguard the Yard's and the Owner's interests. A well-qualified Owners Rep is also very helpful. Still, they must also positively manage the Owner and Yard relationships and not engage in scoring points. Contracts and Project Management Contracts should be comprehensive, clear, and concise, covering all agreement aspects without complexity or overreliance on legal speak. Contracts of often misunderstood or selectively read. It is useful to write a summary of how they flow for your own edification before committing to anything complex. Owners should consider ways to manage potential currency and inflationary risks, such as buying currency forward, buying equipment early, or simply understanding that a risk exists. In an inflationary world this goes a long way to wards mitigating project risk so show flexibility. When building in Turkey, the ownership of the hull and all fittings remains 100% with the owner providing all outstanding invoices are satisfied. This law in Turkey is designed to provide owner assurance throughout the building process. Project specifications and quality standards must be clearly defined to avoid future surprises for either party. Project progress should be verified, and both parties should clearly document the remaining time. For personal and cultural reasons, the Yard will always be tempted to insist that all is on time when that is not true. The time to discuss delays is when there is time to effect remedial action. There is no time to have this conversation after a missed launch date. Payments should be tied to agreed milestones rather than a monthly percentage to account for potential project deviations. Yards and owners' sea trials need to be clearly specified, with minimum requirements outlined. Defined Terms Owner/Owners – "you," the body that has commissioned the build and, under the law in Turkey, is the legal Owner of the vessel in build. Yard – the shipyard, in this instance, Naval Yachts Naval Yachts – see Yard. Artnautica is the design authority for the basic LRC and XPM ranges of high length-to-beam hull ratio and rugged Explorer Yacht designs. Final Thoughts There will be a constant stream of issues toward the end of your build. How we approach those problems greatly affects the journey itself. There will be points where murder is considered by both parties, so keep your eye on the end game and adjust your responses with that goal in mind. There are always solutions, whether acceptance, an engineering alteration, or an alternative path. The owner and the Yard have the same objective: a successful launch. It is best to resist the temptation to blame or otherwise become adversarial. This photo walks the talk. For more information and to see how our own build progressed, www.exploreryacht.com

This week, we will return to the subject of longitudinal stability. It's a pet peeve of mine. Following a recent blog, we have established a measured KG (Center of Gravity) for a given load condition, allowing us to override some prior assumptions with factual data. Before going further, though, I'd just like to repeat a previous opening statement: Dunning Kruger - "When a person's lack of knowledge or skill in a certain area causes them to overestimate their competence." I'm not a Naval Architect! Injecting Factual Stability Data First, we ballasted the forepeak tanks with just over 4T of fresh water to control our 9s roll period. It's still high at 7s, but at least manageable in our very lightship condition (targeting 5.2-5.5s in "Arrival" trim). We then undertook an "Inclining Experiment" to establish the lightship Center of Gravity (KG) for this load condition. We then used this known figure in our calculation model (MaxSurf) and set the various load conditions for Arrival Loaded, Departure Loaded, and Arrival - Launching Tender. We have a best guess for the water ballast under these various conditions (Via Steve Parsons at Eyes Expeditions, ex-FPB commissioning Captain) and assumed Departure is 100% fuel and Arrival an extreme <20% fuel. MGN 280 for stability - Category (0) Unrestricted We can play with fixed and water ballast under various conditions such that the estimated stability results satisfy the requirements of MGN 280, Section 11.3, Motor Vessel under 24m LOA. (Motor Vessel operating in Category 0 as per Section 11.1.1.2) What were we looking for exactly? I'll quote from MGN 280 directly: The curves of statical stability for the loaded conditions should meet the following criteria:- The area under the righting lever curve (GZ curve) should be not less than 0.055 meter -radians up to 30 degrees angle of heel and not less than 0.09 meter - radians up to 40 degrees angle of the heel or the angle of down flooding if this angle is less; The area under the GZ curve between the angles of the heel of 30 and 40 degrees or between 30 degrees and the angle of downloading, if this is less than 40 degrees, should be not less than 0.03 meter - radians; The righting lever (GZ) should be at least 0.20 meters at an angle of the heel equal to or greater than 30 degrees; The maximum GZ should occur at an angle of the heel of not less than 25 degrees, and After correction for free surface effects, the initial metacentric height (GM) should not exceed 0.35 meters. We also get: Trim: by the stern under all conditions, even keel accepted. List: can be adjusted; not important at this point The angle of Vanishing Stability:>120 degrees Tank conditions: for Arrival and Departure Fixed Ballast: total AND location throughout the vessel for a full compliment, inc. tender and crew of 8 people. Below are GZ curves for three load conditions. Departure with full fuel, Arrival at 20% fuel Arrival and launching the tender (WORST CASE). The curves show an unusual double hump feature. This results from the saloon beginning to assist in buoyancy as the deck edge submerges. Unlike many motor yachts, the saloon windows are bulletproof, creating a watertight enclosure under such conditions. Results of Stability Tests and Calculations This work resulted in the following conclusions: We need 2.25 T of lead ballast at 4 locations along the hull. Ballast will also balance an existing permanent port list sans the tender. With the addition of lead ballast, we have sufficient water ballast to compensate for fuel usage under Arrival conditions. We can launch our Tender without listing dangerously. We can remain within MGN280 Stability Criteria in all realistic load conditions. Vanguard has a long, narrow and hopefully very efficient hull shape. She will roll gently being generally on the tender side without stabilizers operating. She is in absolutely no danger of becoming unstable under most conceivable conditions. When she does roll it will be with a good margin of safety and little risk of consequential down flooding. Job well done!. Further confirmation of the above will happen when MCA officially approves another test and scrutinizes the resultant Stability Book. My thanks for their indulgence to: Dincer Dinc is the Technical Director of Naval Yachts. Eyos Expeditions from some awesome contacts! Chris Leigh-Jones I have heard a figure of 180 degrees bandied about the Angle of Vanishing Stability (AVS). In other words, a rollover. The reality of that is something different, and if it ever happens, then it's probably your least immediate worry. Refrain from being attracted by this statement; it's for marketing pamphlets only. Practical stability and avoiding down flooding when heeled are of greater interest to us.

This week, we visited METS in Amsterdam, one of Europe's largest marine trade shows. An opportunity to meet friends and suppliers in a single visit. It is simply huge so if you visit, take comfortable shoes. Victron Energy solar input, forcing what we need One such supplier present was Victron Energy who provide all our low voltage electrical equipment so it was a great opportunity to speak with their technical staff. Having switched the system live, we noticed a problem; it did not work as anticipated! The system takes 415 VAC 3 phase from our 2 by 60kW.H power batteries and feeds it to 220VAC and 24VDC power. It also takes input from our theoretical 6kW of DC power. Victron MultiPlus controllers are "grid pass-through" devices. In other words, they use "Grid" power as their main source and "Solar" power as the backup. Batteries keep 100% topped up in the event of emergencies. That's not much use when your "grid" is a set of big batteries. We need to use Solar power preferentially and only draw from our propulsion batteries when the sun does not shine. There are two potential solutions. Victron has an Energy Storage System (ESS) option for solar-based installations. It is pretty useful and function-packed but quite complicated in the implementation and still with a focus on an unlimited "grid" connection. More recently, they have updated the MultiPlus control software with a "Preferential Solar" option where the operator can force the system to take power from Solar to the maximum available and then draw Grid power only when batteries deplete to a predetermined level. It's a little more complex than that, but enough for now. Does it work in practice? See the illustrations above. The first indicated Grid consumption at a specific moment in time over two days. Grid input = "0" Ha! The second showed solar input when we enabled the feature on day 2 (in the middle of the graph). We can see an increase in Solar input, which is still quite low, but also look at the (blue) line indicating the battery charge state. They are full by 14.00hrs that day so that the MPPT controllers will return to zero, and the system fully charges. Red columns are AC & DC loads. These have increased slightly as additional systems come on line day by day. So, we can tick that box and move on. DMS Magnusmaster Stabilisers There followed some good news as we visited DMS Stabiliser in the Netherlands, in the form of Patrick Noor, his family, and company. Smart, innovative, and client-focused would be my takeaway. I'd also throw in genuine for good measure. We targeted our day at understanding how their Magnusmaster system worked in practice. We selected Magnusmasters as they will fold away from damaging ice or logs and can break away in the event of impact without risking a hull breach. Two rotating cylinders, one on each side, generate a maximum of 4 tonnes of reaction force across our narrow 5.2m beam. That is a significant lever arm keeping us level. A practical demonstration used a yacht owned by a client of DMS. Testing a stabilizer on a dead flat Dutch canal is not effective proof; they can, though, run them in antiphase to force a roll. Refer below to a video of what happened on a yacht of a similar beam to ours. Force the antiphase and the roll is both immediate and significant. Switch to "in phase," and it stops within 1 cycle. We look forward to using these in anger as soon as the sea trial begins. For good measure, I've also included a video showing deployment time; for the forgetful among us, they will fold automatically when the transmission is set to neutral. Keeping it light for this week, we also started both engines to connect the drives. For now, it's a wrap. Chris Leigh-Jones

It's been a while since our 220 VAC this system had much attention but now is time to review and test the major components. There is nothing particularly novel in the design excluding a three phase integration. Be warned, it is a mind game; you may get a headache reading it. Power Input and Conversion Solar: Four Victron Solar Smart MPPT controllers each take power from one of four large solar array (total 6kW Pmax) . Solar panels are arranged into four groups in series/parallel to create 96VDC maximum voltage such that shading effects are limited and we remain within voltage safety limits. Solar output is converted to 24VDC. All electrical connections are on the underside of each panel and away from potential trips or other electrical hazards. They connect to the system via an MG Systems battery management system that houses the main DC Bus Bars. As Solar panels are always "live", each is fed through a dedicated breaker for future maintenance. Shore Power - Victron Skylla-i - these are two single-phase unidirectional isolation transformers in parallel, controlled from a single Skylla-i Control unit. They accept 120VAC 60Hz to 220VAC 50Hz shore power and convert it to 100 Amp (max) 24VDC output. Conversion wastes some energy but makes us independent of single-phase shore power frequency (50/60 Hz). Skylla also provides galvanic isolation for the hull from any stray electrical currents in the dock. Input current can be limited to save continually tripping shoreside breakers. (We can charge from 3-phase shore power 50 or 60Hz, though that is outside the scope of this Blog.) Three-phase from Propulsion Batteries - MultiPlus inverter charger - these inverters are bi-directional. In other words, energy can flow both ways. They take power from 415VAC bus bars for 220VAC and 24VDC distribution. One Victron Multiplus provides power to one of three 220VAC distribution circuits (L1, L2, L3). MultiPlus also provides 24VDC via a bidirectional link to the DC Bus bars. Three times 5KVA (about 4kW), allowing a maximum system load of 12kW. L1, L2, and L3 each power its own family of consumers to try and keep an acceptable load balance across the three legs. These MultiPlus allow our hotel system to tap into the huge 120kW.h reserves of propulsion power batteries in addition to 21kW.h of house batteries. Note the small green "Inverter " LED in "ON" as we are temporarily drawing power from shore-side three phase. Power Storage and Consumption DC Distribution uses MG Systems MG Master LV (battery management controller). This controller is the big brother of the Victron Lynx DC distribution system and is fully compatible. The advantage is the 24VDC moves from 500 to 1000 amp rating. It interfaces with the Victron Cerbro GX controller and modulates all high-amperage DC input and output, the house battery charge, charge rate, and charge temperature. It also fuses all high-amperage DC input. MG System Master LV Controller system including main 24VDC Busbars and line fuses. Solar input from MPPT is seen as the bundled black wires top right. MultiPlus connections are the red wires tagged Chargers/Loads, House batteries the red wires bottom left tagged Batteries. Battery charge signals come from the strip tagged "Battery CAN", bottom center, Cerbro GX is linked to "Aux.CAN". Our three by 7kW 24VDC Lithium house batteries are from MG Systems. Victron Cerbro GX controller monitors these batteries via the MG Systems Battery Management System. The house battery charging current is limited to 80 amps per battery as the in-feed power < 2kW (MGN280) regardless of other safeguards. For this, we have used the VE Direct CAN comms system and a facility tagged DVCC (Distributed Voltage and Current Control). It was cheaper and a lot simpler than providing a dedicated, fire-resistant, and externally vented containment. Engine starter batteries are deep cycle lead acid type. They charge from the John Deere engine alternators, plus a small trickle charger as a backup. It's their only job so our engines become self reliant (dead-ship). A dedicated battery at the helm station ensures extended VHF (GMDSS) emergency calling. Navigation equipment is electrically isolated from any other 24VDC system using a small Victron DC/DC converter. This converter is galvanically isolated and short-circuit protected (think lightning). Excess power capacity on the 24VDC system (from solar or shore power) can also trickle back through the MultiPlus to three-phase distribution and, from there, slowly recharge the two by 60kWh main power batteries if the Praxis hybrid power system is live. So we now have three ways to keep a charge those huge power batteries (I just checked if that was working, and it is!). Of these three, direct charging from the 70kW Praxis hybrid drive is the quickest. Power Control and Monitoring Data transmission from all connected components uses the proprietary Victron VE Direct CAN ethernet, in which all sub-components remain compatible. It is dedicated to only this system. It's a thing of beauty, to be honest, nice design from Victron. Left is the Cerbro GX. Black connections are the Screen HDMI and power. Blue are the 3 VE CAN with a CAN termination block to the right of them.. Solar output is shown in the photo above, right, at 1231kW, that is the maximum system requirement at that specific moment. 967W is charging house batteries as the system went live overnight, 175W going to DC consumers and a small trickle going in to warming up the MultiPlus inverters. The system's hub is the Victron Cerbo GX and a Victron Touch control screen. Both sit at the Helm Station. The GX is a small computer that allows each device to communicate. It does some controlling along the way. Connected to that is the Victron Touch display. We can view and control the system remotely via the Victron VRM Web portal using the Starlink comms system (or not in Turkey!) or locally on a cellphone via the Victron Connect App using Bluetooth. That connection went live yesterday. How is the head? If it is as bad as mine after writing this, then try this background read from Victron Energy; I found it very helpful: HERE Chris Leigh-Jones Our electrician METS (Niazi Bey) identified an unanticipated failure risk. The MultiPlus has a long mean time between failures so we fell in to a self satisfied lull. However as they were synchronized as a bank of three, failure of 1 was failure of 3. In other words we went dead ship within a day or so. Not a great outcome. The answer was a rework of the logic such that the three phase lines could be linked directly with single phase L1,2,3 bypassing the Multiplus. We can then use one of the remaining two MultiPlus as a temporary house battery charger and just keep an eye on charge state until the system can be brought back on line at a later date. Nice catch Niazi.

Dunning Kruger - "When a person's lack of knowledge or skill in a certain area causes them to overestimate their competence." I once worked on a research project adjacent to Newcastle University School of Naval Architecture, home of Froude and Reynolds numbers, Parsons, Turbinia, and all that followed. That does not necessarily make me much of a Naval Architect. So, we faced the question of stability for our floating investment of 3 years. Our fallback is twofold, "Show me the science" and "Who has existing knowledge in this field?" This learning stage is probably not for the faint of heart. These long, skinny, round bilge hulls don't behave like your typical "Down Easter." They may also look like a yacht hull, but there is no keel; our points of reference are few and far between. So let's start with the "Show Me the Science." Our Yard uses two hull design programs, Orca3D (same as some FPB designs), and Maxsurf. The issue was that the two reports we had did not agree with each other; the end result was consternation. Examination (by Naval) revealed one had set the baseline at the bottom of the skegs and one at the bottom of the canoe form body of the main underwater hull. As the skegs played little role in overall stability, this report was rejected. Also, we always expected to add an amount of permanent ballast and fluids to increase stability from the true as-launched "lightship" condition. Any fluid added to tanks will lower the CoG and reduce the roll period (see drawing below). So, having established an agreed way forward, we need two pieces of factual data. Firstly, to undertake a preliminary "Inclining test" to establish a longitudinal Center of Gravity (CoG). An official inclining test will be undertaken later, under the watchful eye of our UK MCA Surveyor. Secondly, we will have a close approximation for the distance between the CoG and the metacentric height (GM) for this load condition. Once we have that data, then revert to the CAD model of the underwater hull and superstructure, input the known conditions for GM and CoG, and then extrapolate stability data for various other load conditions, including Arrival, Departure, permanent ballast, and swinging the tender outboard in whichever load conditions is the least stable. Autnautica has also agreed to model this for us as an allied third party. Who has prior knowledge? For this, we turned to Eyos Expeditions, specifically my friend Magnus Day and, latterly, his buddy Steve Parsons. Magnus has spent long voyages on FPB 78, and Steve was the commissioning engineer/captain for many of the FPB Explorer Yacht hulls, continuing his involvement to the present day. Talking about a subject will gain some understanding, but more clarity will be needed to set targets. Our initial intent was to develop three stability conditions. Lightship Loaded/Arrival Loaded/Departure Like FPB from Dashew Offshore, Artnautica designs use water ballast compensation. Too little, and she becomes tender; too much becomes stiff with an added fuel consumption penalty due to increased draft. So we studied the trim "envelope" with knowledge of a good starting point and some hard physical data on trim and draft for her present, unoptimized condition. Lightship No fluids, no lead ballast, Vanguard's launch condition. It is quite a scary place, like a balloon floating on water, but we also know it's unrepresentative of any "at sea" condition we may encounter. Loaded - Arrival This would be our condition after a long passage. Minimum fuel and sufficient water ballast compensation to maintain adequate stability and efficient trim. The input was arrival conditions from FPB 78 with an estimated 20% fuel reserve remaining in our center tank (we might push this to 10% to see what happens), and around 50% water ballast capacity. Vanguard trims naturally by the stern due to my overindulgence in propulsion machinery. To counter this, we will add permanent ballast to restore trim closer to an even keel and alleviate over-reliance on pressing the forward water tanks. We have yet to determine exactly where we will add the ballast as all in the forepeak may bring its own performance issues (Polar moment being proportional to distance^2). Loaded - Departure This will be the third condition we will examine. Full fuel tanks for maximum range, including 2-day tanks, four wing tanks, and our main central double-bottom tank. Marine diesel in each, 0.85 Relative Density. We will investigate the freshwater ballast requirement under these conditions to establish a good trim while minimizing our draft penalties. The calculations will include any permanent ballast, a full equipment compliment, and the tender. Overview of preliminary loading conditions Tank ID Lightship Arrival Departure FW Fore P 0% ?? ?? FW Fore S 0% ?? ?? FW Aft P 0% ?? ?? FW Aft S 0% ?? ?? GW Fore 0% 10% 10% BW Fore 0% 10% 80% Fuel Fore P 0% 0% 100% Fuel Fore S 0% 0% 100% Fuel Center 0% 50% (approx 20% total remaining) 100% Fuel Aft P 0% 0% 100% Fuel Aft S 0% 0% 100% Fuel Day P 0% 100% 100% Fuel Day S 0% 100% 100% GW Aft 0% 10% 10% BW Aft 0% 10% 80% Glycol P 0% 100% 100% Glycol S 0% 100% 100% Ballast (Lead) 0 ?? ?? Note - the designs use water ballast to compensate for fuel usage. FPB 78 used approximately 50% water capacity for fuel bunkers between 14,000 and 4000l. The roll performance at the lower end of this was towards "tender". The output from this work should be threefold: We will know our extreme conditions and always be able to operate within a safe envelope of vessel and crew safety. We will automatically obtain the data we need for our Stability Book. This is a commercial requirement for MCA Category (0) Certification, not strictly necessary for private operation, but we want it anyhow. We will know what to expect as we launch the tender over the side of a rather slender hull and can take some precautionary measures as needed. We hope to report back on the results of this work in the coming weeks. In the meantime, my thanks for their indulgence to: Dincer Dinc, Technical Director of Naval Yachts. Eyos Expeditions from some awesome contacts! Chris Leigh-Jones I was talking today to my very patient wife, Sebrina. I'm old, I'm retired from house building, scared hands and old bug bites. I should perhaps be joining a few men's clubs and playing golf, but every morning seems to bring a new challenge, demanding use of my remaining grey matter. Adventures are best in the telling, and this has been quite the adventure. Close now, so close (and I can't play golf!).

Our XPM-78 Vanguard has been making waves recently, particularly after being featured in a popular video tour of NavalYachts. This has sparked a lively discussion comparing Vanguard with the FPB-70, a successful series designed by Steve and Linda Dashew. As an explorer yacht builder , we find this comparison fascinating. Let's dive into the facts and see how these two expedition yachts measure up against each other. Vanguard was recently featured in a friend's Video following his trip to NavalYachts. It was a popular video attracting many comments, including a few comparing Vanguard to the successful series for FPB designed by Steve and Linda Dashew and built Circa Marine. Rather than becoming anecdotal at this point, what are the factual similarities and differences between our explorer yacht Vanguard and FPB-70? FPB 70 - acknowledgement to Circa Marine Firstly though, there is a confession to make, the owners of the explorer yacht Vanguard (us!) initially wanted an FPB 70 (think Buffalo Nickel). A competent and rugged explorer yacht design capable of being handled by a minimum owner/crew of 2. The only problem is that they will never make another to that design. So rather than roll belly up and opt for the typical US "Down East", we decided to build our own. XPM-78 under construction at Naval Yachts XPM - eXtreme Passage Maker future-proof (possibly diesel-electric) portfolio (78, 85) FPB - Functional Power Boat has been described as a paradigm shift for motor yachting Enter designers like Nigel Irens or Dennis Harjama, proponents of high "Length to Bean" ratio, efficient ocean-going yacht designs. Of these, Dennis of Artnautica is the most active in the space having plans from 58, 65, 68, and, latterly, 85 feet LOA. Comprehensive data on FPB-70 is sparse. With some digging, these are the comparisons that we can find and the differences we have highlighted. Vanguard vs FPB-70 Yacht: The Hulls To look firstly at the hull itself. FPB-70 yacht is the same length (LOA) but slightly wider and has a 20% deeper draft. XPM-78 design uses electrical and hybrid power, and that concept demands the lowest hydrodynamic resistance to achieve any practical range. Vanguard sacrifices internal volume to satisfy this, and the seakeeping is yet to be proven. Suffice it to say; Vanguard is a slightly skinnier hull for the same length. Her forefoot is slightly more pronounced to facilitate mounting the bow thruster forward in the narrower beam. Additionally a small bulwark has been fitted for aesthetics and to help keep the foredeck dry(er). She will carry the same crew and has approximately the same internal configuration, just a little less space in comparison but still large by most standards. Notable, though, is that both designs target MCA Category (0) operating envelope; they will both run in the arctic and antarctic regions in the summer months. Stability is perhaps more a marketing figure than something of practical importance. In theory Vanguard has no angle of vanishing stability and FPB-70 has 140 deg in its specification. Both angles are well past a knock-flat and if you ever find the vessel in that position then rollback may be the least of your worries. Let us agree they are both unusually stable and resistant to flooding. Let us also hope the motions are not too stiff then leave it at that. ( I remember once carrying a bulk cargo of finished steel and unable to ballast the wing tanks, horrible motion that went on for weeks. ) Unit XPM-78 FPB-70 UK MCA Category ​ (0) (0) LOA m 23.8 23.8 LWL m 23.8 23 Official length m 22.4 21.3 Beam (deck) m 5.13 5.66 Draft (50% load) m 1.3 1.55 ​Draft (max @ skeg) m 1.3 1.55 Air Draft m 6.4 6.4 Displacement kg 41,000 50,000 Fuel litres 14,000 15,100 Water litres 7,000 10,000 Cabins (double) ​ 3 3 Read also: Designing a Robust Hull Structure Vanguard vs FPB-70 Yacht: Performance I am wary of quoting exact figures for performance as it is not, in truth, an exact science. It is tempting to simplify this to say that the performance and range are similar. The only notable difference is the maximum speed of Vanguard being somewhat over the theoretical hull speed. She has duplicated diesel with an additional twin hybrid drive to boost performance. Not a practical long-term option, but if you want instantaneous speed, then she has the edge. ​ Unit XPM-78 FPB-70 Range (20% fuel reserve) NM 7000 @ 9 KN 5000 @ 10.5 KN Max angle positive stability degrees 180 140 Cruising speed KN 10.5 11 Top Speed KN 15 12.75 Min Crew ​ 2 2 Vanguard vs FPB-70 Boat: Structure Moving on to the yacht structure, XPM-78 and FPB-70 boats are again similar. Both have relatively massive scantlings compared to acceptable construction codes; both are marine-grade aluminum and have identical plate thicknesses. The design is equivalent, with five water-tight compartments and extensive use of double-skin tank construction. Vanguard vs FPB-70 Boat: Propulsion On the topic of yacht propulsion, there are some notable differences. Vanguard XPM-78 uses twin Brunton's Autoprops. These are similar to sail drives meaning she can voyage on a single engine without windmilling or incurring much drag. Thus engine operating hours are considerably reduced. She also has a modern diesel electric hybrid drive as the owner's indulgence. Great for in-port maneuvering (with full Dynamic Positioning) and even better for those huge 120kW.H power storage batteries meaning no generator running in port or at anchor, ever! It also means she can charge batteries by running the hybrid drive de-clutched from the propeller resulting in over 90kW charging capacity. Similarly, the solar arrays are larger, further increasing her power independence. Read also: Hybrid Marine Propulsion - Why Bother? Vanguard vs FPB-70 Yacht: Summary Other differences noted boil down to personal choice, the tender design, and the type of stabilizers, painted or bare aluminum, interior facades. These are not fundamental differences and could fit either design with no notable modifications. So, in essence, to answer the initial question? Yes, very similar, with the XPM-78 reflecting more recently available technology. However, differences aside, the XPM-78 gives us all that we were looking for in the FPB-70. We also gain a Yard that will indulge our personal biases in a new build. To conclude, if any reader has considered an FPB as their dream yacht, now consider an XPM a viable, attainable alternative in this size range. Useful Links - Berthon International FPB-70 details - HERE - FPB-70, Buffalo Nickel Blog Site - HERE - Steve and Linda Dashew FPB Blog Site, FPB-70 details - HERE - Artnautica LRC/XPM yacht designs - HERE - XPM-78-02 specification - HERE Dincer Dinc/Chris Leigh-Jones Read also: Sea Water Intake System Design Proves Problematic Read also: Yacht Fuel and Water Tank Capacities

Occasionally, we find ourselves influenced by the briefest of conversations. Such was a recent experience after speaking to Steve Parsons of Eyos Expeditions. Steve recently brought FPB 78 (Ugly Betty) through the North West Passage. Previously, he was the commissioning captain for FPBs launched at Circa Marine. Short of Circa Marine themselves, Steve probably knows more about FPB performance than all but one man alive. So, I was in for quite an education, and I'll report on just two aspects of that in this Blog. FPB has a much-vaunted capability to surf in a following sea (see the Youtube video below of Cochise FPB 78). Waves slowly pick up the stern, pushing the hull forward as she slips down the wave. FPBs limit the bow digging as speed increases, preventing bow steer and a potentially dangerous broach. Watch the many videos available, and you can see how comfortable they seem to be in this condition. Steve Parsons described this situation in graphic detail. So far, so good. Steve also talked about his experiences during FPB 70 and FPB 78 commissioning and sea trials. When a vessel designed for a hull speed of around 12 KN finds herself surfing over 20 KN plus, this is outwith the experience of most sailors or naval architects. The hydrodynamics become unusual, and the forces in play are quite large, giving rise to two issues as detailed below. Rudder balance A typical rudder design for a displacement hull installs the stock of a spade rudder at about 25% of the chord distance from the leading to trailing edge (1/4 chord line). An area in front of the rudder stock moves the center of pressure forward, reducing steering ram torque requirements as forces act in unison on both the leading and trailing edges. A degree of imbalance reduces, and the situation is unaffected by the diameter of the stock itself but only by its axis. (Image is a stock description of rudder terminology.) There was a significant increase in force on the rudder's leading edge at surfing speeds. The effect was to move the center of pressure forward in front of the rudder stock. The steering rams could not overcome the increased torque requirements, and the steering became momentarily frozen. A solution employed was to decrease the area on the leading edge by positioning the stock to around 18% (figures are approximate). Steve was referring to an FPB 70, but wait to quote me. The effect was tested by uncoupling the steering rams when tied to the dock and running the engines at full load. If the rudders tended to slam hard over, then the potential for imbalance existed. In my vernacular English, "this is a new one for me." On Vanguard, the area in front of the rudder stock axis is 21.2% (18% <21.2%> 25%). It's too late to reposition anything, though we have the clearance to add material to the trailing edge, producing the same effect should sea trials indicate the need. Hydraulic loads The second issue was with the autopilot. I would start here by stating that FPB used the excellent Simrad autopilot, and the company was very responsive. Transient pressure spikes on the steering rams played havoc with the control logic within the autopilot unit. This novel condition triggered it to default to "safe" or "standby" mode, requiring a software modification. At the same time, the steering ram capacity was increased to provide a higher steering force, moving away from a potential hydraulic stall condition. An alternative would increase the torque arm length, though this was not geometrically possible on the vessel in question. Vanguard has a commercial Wills Ridley steering system (see below), much in common with the Kobelt systems used by FPB. Naval Yachts has also maintained the tiller arm swing and resultant leverage. Our only significant differences are independent rams and pump per rudder and a deeper aerofoil section to the rudder blade as it wraps around the oversized rudder stock. It may make no difference, but we retain the potential to increase the ram capacity or tiller torque arm length within our design. Roundup There is no rule book for when a design pushes at the edges of accepted practice. Some are horrified by this; others run towards it. It is true, though, that few of us wish to end our days with the description of "He was normal." Thank you, Steve Parsons, for your unique and helpful insight into the world where we will willingly play. Chris Leigh-Jones Useful links Eyos Expeditions: https://www.eyos-expeditions.com Circa Marine: https://circamarine.co.nz