Pontoon shape

Earlier this year I built a small pontoon boat as practice for building a larger boat. I basically built 2 narrow Jon boats with a deck connecting them. It has worked perfectly as intended but I've only powered it with a trolling motor so far. The boat I built ended up 9'x5.5'.. it's very stable when the water is flat but being so small waves push it around a good bit.

I want to start slowly working on the pontoons for the larger better boat but I don't know the shape I want to build them. Glen L has plans for the huck Finn pontoon. Is that a good route to go? I want to build something 16' long that will be powered by something around 20hp. I don't care about speed but don't want it slower and more inefficient than it has to be. The boat will be used for swimming, fishing and having some beers out on the water. I basically just want a floating dock that can be moved around and live on a trailer. How important is the shape of the pontoon? If I built a similar design like I have now that's larger would chop still move it around as much? Trying to find a good balance of ease of build to performance.

 

http://www.common-sense-boats.com/fishcat.html

 

This looks great. Would it be possible to expand the deck? I'm looking for the most amount of deck space I can get.

 

Canoe shape for pontoon would be hard to beat. Did a boat with canoe hull with a small flat planning area in stern. This boat was very fast with a 5hp, over 20 knots.

 

i kinda focussed in on the phrase "don't want it slower that it has to be"... when i posted the fish cat design and before i had a really digested the rest of what you were saying...and before i had a look at the Huck fin

basically the Fishcat is likely the more mobile of the designs as the pontoons look look to have a finer entry, some rocker but a pretty flat stern the latter is probably better for planing ...
there is also a lot of flare built into those pontoons based on the lines drawings.

no line drawings for the huckfin but there is a pic of two pontoons side by side here
http://www.glen-l.com/designs/house/dsn-hfnc.html
they aren't as tapered or flared, there really appears to be a curved up stern on the finished pontoon that likely isn't ideal for planing... less flare might equal more lateral resistance (less likely to drift laterally in the wind, & harder to turn when traveling)

but based on what you want to do the huck finn seems to be more suited, ie carry more wieght forward on the pontoons etc...