I am building a pontoon boat for a shallow bay with lots of sandbanks. A regular propeller would be bent to scrap pretty quickly in that setting as soon as it collides with sandbanks, and a jet drive or pump drive may get clogged with sand. But couldn't I use a propeller that's built like a screw, or tread? Would those work at all? Do they exist?
I reckon it would simply work the boat over the sandbank in the worst case scenario, rather than getting stuck on it. Even if it can't do that. it would hopefully be pretty sturdy - but again, does that exist at all?