Re: Tri hull trailer
I've launched a few larger boats on full roller trailer which were a real job to get unhooked once on the ramp. The boat's weight would remain against the winch and there was no way to get far enough back into the water to let the boat float free with that type trailer I used to disconnect the winch and wrap the lead rope well around the bow stop so I could easily release it once in the water. While I never had to launch that one alone, I would toss the lead rope to a buddy on the dock to pull the boat over to the dock while I parked the truck and trailer. I'd then just run and hop in the boat, warm it up and be on my way.
I've had a few roller trailers on which the boat still didn't move very freely, but after switching to new Yates rollers, it's slides right off.
I've had several trihull boats, all were on bunk or roller bunk trailers. Keeping them low is pretty important when it comes to launching.
There are several type trihull designs too, some are no more than a deep V hull with two outer hull formations and others are true tri or 'W' hulls ending in a true three hull shape, while others are more just flat bottom hulls with a tri hull bow area. On the true 'W' hull boats, its usually easiest to set up the bunks to set in between the two outer hulls and the main V hull. Roller bunks work well on the flat bottom and mild V bottom hulls, and many can be put right on a standard full roller trailer.
My Starcraft Capri and Duo Gypsy both worked well on standard trailers.
The good thing is that most of those hulls were rock solid and fairly light. My Starcraft was only about 800lbs plus the motor. The floating boat was only about 1500 lbs with fuel, a 120hp Evinrude V4, seats, fishing tackle, coolers, and my home built casting deck. The trailer was a 12' tire TeeNee that came with another boat. I never felt it was under sprung or overweight at all. I later put that boat on a Load Right 19-2500 trailer which worked fine, a bit heavy but it made it nicer to travel farther.