I have 3 boats, a couple smaller sail boats (13 & 18) and my Formula 180.
I really wanted a way to get them off the trailer.
I have a large barn, so I built a lift by gluing and bolting 2x6's and using doubled 2 x 4's for vertical supports. My dad's an engineer, so I confirm my lifting capacity ~4000-5000 lbs.
Marinas use jacks like that all the time I've never seen one fail. I will say however that if someone staples, or screws carpet to the plywood it'll do hell to gelcoat.
