Interesting; but I don't think I want to use plywood for a body that's going to be in the water as shown in the video.
I thought the same thing and figured if they used marine grade wood and sealed it, it'd probably be pretty tough.
Verticaltrx; I have the nortrac dozer weighs in around 7000lbs, I have been very pleased with the amount of work I have done with it. It's handy in the woods because it isn't so big that it destroys everything. I have pushed 100's of tons of dirt rock etc... and it has not let me down. A lot of folks say a small dozer is worthless, I have to disagree completely.
Handirifle: when you start that project show some pictures