Looks like we have a basic shape in mind for the structure over the stern of the boat, even if we don’t know exactly what to call it. The tasks for this tower are 1. Place the wind vane self steering gear well up in to the airflow behind the mainsail, 2. Mount the radar dome, 3.mount the GPS antenna, 4. Provide the rearmost anchor point for the cockpit shade Bimini, 5. Hold a backup VHF antenna in a pinch. It has to be wide enough for the tiller to swing a proper arc, but can also be a limiter for keeping the rudder from slamming broadside out of control. We also want it to be a sturdy handhold for climbing those steps to/from the stern.
So this is a cardboard mockup with legs of about four feet tall, raked back for looks but also to center the top platform where it best suits the wind vane. The width has been determined by the (arbitrary) placement of the previously made stairs, and the general idea for this thing has been in mind since first watching the Volvo Ocean Race boats a few years ago, with the little towers on their sterns to mount all the comms gear.
And no, the real tiller won’t look anything like this ugly grey PVC pipe – that just did the tiller angle measuring role.
One wrinkle in the construction is that this tower will have to be remove able for the road trucking. So I think we’ll build 18-24 inch permanent stubs up from the deck, then sleeve the rest of the legs down over the stubs, with threaded rod inside to bolt the tower in from the aft cabin. Also need to figure out an internal conduit to easily hide all the wires from tower-mounted gear.
If anyone has any warnings, words of advice on stern towers, or info on the minimum suitable height above deck we can run the radar dome, please comment.