one thing to consider is if the thing needs to come off easily for travel/ haulout.. then remount in the spring. mine has a plate that's mounted to the roof, then the wing just has some machine bolts that mount to that for easy on off.
was thinking about a hinged system that would let it flip back towards the deck..didn't work out in my application.
38' holland. I bought a large boom on craigslist. I got the cad drawings from seaview for their commercial mast. They wanted $4000. I went to Essex engineerings in Lynn ma and with the drawings pretty much duplicated for a third the price. I painted and mounted everything. I haul the boat a couple miles up the road and need to remove it so I drilled and tapped the backing plate and use terminal strips for wiring. It's height is about 48"
I dont pull big spreader bars here. Mostly baits and lures. I like the idea of being able to take the mast down when needed-had not thought about that. The swing out riggers with the L bracket to mount on the roof looks like it would work on the Duffy. What length poles do you guys see on a 31 ft boat. Im thinking maybe 18ft?
You should check out Nautical Creations. Not what is on the website, but if you call him, Bill, he will email you a bunch of custom masts he has made. He emailed me a bunch of masts, and is currently building me one. Very fair price to say the least. I will let you know how it turns out. Good luck.