: Put a nut and washer on each end of the U-bolt and leave this well down into
: the pour. This will act as a "deadman" and resist upward force
: much better than just the U-bolt shank or a nut snugged up against the
: bottom side of the deck.

: Randy

A lot of those u bolts already come with a flat metal bar that spans the open ends. After inserting the u bolt, get that bar across the two threaded ends and secure it with the nuts. No need to tighten those nuts too tight. The epoxy will keep the nut from spinning off.

Whether you use washers or a bar across the threaded ends, consider packing in two or three pieces of glass cloth, anything from 2 inches square to the size of an index card. Epoxy resin that saturates that will provide a very strong reinforcing component that should spread any stresses over a much larger area.

Those glass cloth scraps should also give you a bit of "springiness", pulling the ends of the u-bolt into the boat. You can then pull out as much of the bolt as you wish to have exposed, and hold it in place with a bit of duct tape.

You don't need too much of the u bolt to be exposed, just enough for passing a 1/4 inch rope or bungee under it. You'll probably want to pass a piece of 1" flat tubular nylon webbing through, too. This will give you a decent carrying strap, and since most of these are rated to 2000 to 4000 pounds breaking strength, you should have more than enough capacity for a 400 pound load. I'm just wondering if the wood can take that much load. If you have to lift the filled boat from the water, I'd suggest turning it over first, and lifting it with the cockpit on the bottom so most of that weight can drain out.

Just a few thoughts

PGJ