I know that this forum probably draws more attention for woodworking and fiberglassing than electronics, but I thought a few people might find this electronics project a bit interesting. When I registered my Madness proa here in Thailand, the law requires I have navigation lights installed first. Well, how do you get the navigation lights to shunt on a proa? I have quite a bit of experience with electronics (mostly on robots and airplanes), so I thought “why not build a custom shunting navigation lights and sailing computer while I’m at it?” 
So we built a solar charged, battery powered, Bluetooth controlled light that can be placed on any of the four corners of the boat and light up appropriately. There are exactly four states that the light can be in: port sidelight (red), starboard sidelight (green), vaka stern light (wider beam, white), and off (ama stern is always off, and all of the lights can be turned off during the day too, of course). We bonded a stainless steel plate to the deck and mount the lights using really powerful magnets in the light base plate, although, I’m not 100% confident in this approach if a wave comes over the top. We may change it. Here is a picture of it on the vaka:
And this is on the ama:
Here is what it looks like inside. It isn’t anything pretty, just hand wired and soldered:
If you look at the base plate on the top of the image, you can see the 5 stacks of neodymium magnets that hold it onto the deck plate.
Turning on the lights, here is the red port side light on the vaka:
And here is the green starboard side light on the ama:
The lights themselves are standard 12V, 3W “eagle eye” LED lights. I tested them by having one person shine one of these out a 12th storey window from an office building on a clear night and I observed it with my naked eye from a 5th storey window about 5km/3nm away, and they were quite clear.
Here is the stern light on the vaka. To get the wider beam, I used two lights offset from each other:
And for completeness, here is the fourth light (which is off) on the stern of the ama:
This shows the 4 LEDs mounted in each device a bit clearer with the red/green sidelights below and the white stern lights closer together above (just for mounting layout reasons).
To turn this into a full sailing computer, we mounted an anemometer, wind vane, barometric pressure sensor and GPS on a carbon fiber tube at the ama to aka mounting point, powered by our main 5kWh of battery pack which we use for electric outboard motor propulsion and keep in the ama just below that point. Here is the battery in the ama storage compartment and the mounting plate for the electronics “mast”:
And here are the sensors at the top of the carbon fiber “mast”:
(And yes, that is a giant gorilla statue in the background. I’m not 100% sure why, but I guess the owner likes “King Kong”.)
I decided to do something a little unconventional and designed the sailing computer to be wearable on my forearm so that I can check it or interact with it while moving around the deck and trampoline. By building the electronics and writing all the software custom for a proa, it supports shunting, updating both the navigation lights layout to the new configuration after the shunt (if they are on) and the direction of the wind relative to bow and stern (since there is a new bow and stern). Here is one image in “ama to starboard” and another in “ama to port” configuration after shunting:
The interface has wind barbs for apparent and true wind on the wind ring as well as light on/off control (center bottom). On the right it shows apparent wind, true wind, GPS speed and bearing and on the bottom is “speed made good” if I set an intermediate destination on my tablet (which I didn’t since the boat is on a trailer in this picture). The screen is an incredibly bright “sunlight readable” 5" LCD screen from New Haven displays (about 3x brighter than a mobile phone) and the computer inside is a Raspberry Pi Pico 2W running micropython. It also has 5 waterproof buttons and a knob, which might someday be used for controlling an autopilot if I can figure out how to build and mount one on the rudders. 
One funny thing I decided to try was to make wind direction “positive to ama” and “negative to vaka” with zero being whichever direction is bow. This just seemed to make sense since a Pacific proa always sails with wind from the ama side regardless of the current ama to port/starboard shunt it is on.
I have a few seconds of video showing the interface for shunting and turning on and off the lights, but I don’t think I can upload video to this forum, so if anyone is interested, let me know and I’ll figure out somewhere on the internet to post it and link to it here.
And just for completeness, here is the hand soldered insides of the sailing computer interface:
Anyway, I just thought I would post my project here in case someone with a proa is looking around for ideas on navigation lights or sailing computers. Since this project is still in active development, if anyone has any thoughts or suggestions, I’m certainly interested.