How do you get a 400 pound boat onto a trailer even from beach wheels?
I do it alone a lot. I have cradles on the trailer, not rollers. They have carpet which I sometimes spray with a silicone lube, it seems to help some. I untie the wheels from the shrouds, roll the boat tilted as close as I can to the trailer. Take the tiller crossbar off so I can get my forearms under the back crossbar. Lift the boat while walking forward. You are lifting less than 100lbs if you cradle it pretty well. It is not A-Cat easy but not that difficult.
Later,
Dan