This product is a totally waterproof, hard but yet flexible polyurethane coating.
I don't keep the boat on the water usually over a few days running however I have no doubt that it will do an exceptional job in not only sealing but protecting these logs and the weight of the coating will no doubt be lighter than running around with 10-20 gallons of water on the inside!.
Also it can be had without the texture like used on a bedliner which makes it a smooth coating.

I actually plan to remove the carpet from my Bullet's trailer and coat the bunks with this stuff to prevent them from holding water soaked carpet against the hull which will eventually causes fiberglass to bubble. That boat is in and out of the water at least 250 times a year so the bunks stay wet!
The textured stuff works well on bunks by giving small air pockets for the water to dry quicker!