Thread: Pontoon Dingy build.

Originally Posted by Rushy

Why a bad idea? To my non technical mind if your pontoon gets a hole (however that might happen), it will leech water into the cavity and cause a list when it fills up but if the cavity is full of polystyrene then bugger all water could enter because the the polystyrene is displacing the air in the cavity.

If a pontoon gets a hole it will likely be at the bottom,if it is at the bottom it can only fill x amount before it has compressed the air inside enough to equal the water pressure and it will not fill anymore(fill the sink and lower a beer glass upside down into it and you will see what I mean),also one is unlikely to hole a pontoon while stationary (when it could possibly fill with water and be an issue), there will be 4 separate sealed chambers so even if say one developed a crack while underway and filled while fishing at anchor while I would be pissed at my shoddy design it still wouldn't sink or even get close to sinking.

The reason I went with a pontoon design is so if swamped(short transom remember) or I have been a dick and take a greeny over the bow it will want to float upright and should be bailable/restart motor fuck off etc.

Pontoons themselves do absolutely nothing for stability until you get in a situation where there is lots of water on the inside of the boat...then they work.
The "stability" people rave about with their various pontoon hulled boats has absolutely nothing to do with the pontoons, hull shape gives(and takes away) stability.