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An Instrument Mast for our Explorer Yacht

Updated: Jan 20

This our final Blog for 2022 following a visit to Naval Yachts. With Christmas now fading, my wife and I would like to wish you all a prosperous and healthy New Year. It will be an adventurous one for us as we take our last son out of school and begin our journey. Until then, we have to complete the build!

Vanguard's build is now coming along well; we can judge progress by the type of questions the yard asks.

This morning's salvo was a series of questions and suggestions for the instrument mast. Radar, Aerials, Lights, GPS, AIS ...... Rather than a knee jerk type answer, it was time to become a little analytical rather than simply judging on the prettiest version. This is how we approached the issue.

Design Criteria

The mast provides several functions and form, in this instance, must follow function. From holding the lights high to supporting the radar, communications aerials to the satellite, and flying the various courtesy flags. Each one of these has some unique requirements. To decide on the final configuration, we first listed what each requirement and it's constraints as repeated below:

  1. Navigation lights are required to satisfy COLREGS requirements; high up is good, and the Port and Starboard lights need to be separated as much as possible.

  2. Radar - we have 2 X Band radars to install. Each needs clear sight for 360 degrees with minimal interference from physical structures that reflect the beam. Additionally, they need to be high enough that the beam does not impinge on the forward flybridge roof.

  3. FLIR (illumination laser and IR and low light visible cameras) - need to be placed with a view of the bow and as high as is practical.

  4. Communications aerials - the flat aerials need to be out of the radar beam and with a clear sight of the sky within a 53-degree vertical cone.

  5. VHF/SSB - whip aerial needs to be as high as possible and separated.

  6. Lightning arrestor - need to be the highest of all.

  7. AIS/GPS/Fluxgate - need to be out of the way of the radar.

  8. Courtesy flag - we need to keep this up in the air!

The Design Process

So how did this process unfold?

First Design

Final Design

Nav Lights