Being that the DNA thread is wandering a bit off topic:

Blindspot wrote: pontoons = buoyancy stability = hull shape as Tagit points out

Now here's something else to consider, my wording is a bit on the poor side, so bear with me:

Pontoons only actually carry a buoyancy benefit when they are situated under the water line with water in/on the deck area itself.

The downside to this means reduced deck space and mobility when compared to a non-pontoon of equal displacement, more physical mass situated at/above and further away from the center of gravity too.

So friends, romans and forum folk - I ask the question:

"What benefits does a pontoon boat actually have over one which has a equitable amount of buoyancy underneath the deck?"

I recognise the perk that if you breach the hull space on a pontoon that you're not going to be sitting on the bottom afterwards, and that if the same happens on a non-pontoon it can turn it into a artificial reef - but is this not negated by either having a conventional hull with closed cell foam inside, or multiple bulkheads?

What am I missing?

underfloor flotation will tend to turn the hull upside down. flotation in the right places will keep the hull upright and floating level. there are some good sources of info i've seen. maritime new zealand has a bit on this. so does US coastguard if you google it.

Fissure wrote: http://www.stabicraft.com/Buoyancy.aspx

That's a inadequate comparison though, simply by making the hull shapes identical the performance characteristics largely fall in line with each other.

From my rather limited experience of owning a boat which just happens to be an aluminium pontoon boat....... and it isn't a stabi or frewza or one of the other many common pontoons out there.

noponies wrote: ITheres a more in depth take on the stabi info here; http://www.mymarine.com.au/stabicraft/stabicraft_advantage.htm I went with a pontoon for the lateral stability as well as the ability to take a swamping and not turn into a stone.