Reconfigurable low-speed multi-hull

Hi all,

I'm looking for a reconfigurable multi-hull idea. The closest I've found is expandacraft, but I don't like their multi-piece pontoon.

What I'd like is a single-piece hollow fully enclosed pontoon with quick-release features for decking, rudder and possibly motor mounts. I'm thinking 500 lbs flotation or so per pontoon tops, length would be 12-16 feet. I would consider watertight openings for cargo similar to what a kayak has.

I'm a foster parent, and my wife and I love fishing, mostly on stock ponds but also on rivers. I've kayaked on the biggest river around here and the current is within the abilities of an out-of-shape old fart in a kayak, meaning I can go upstream without too much trouble.

Under minimal use, I'd want to configure two pontoons maybe 3 feet apart and power with a kayak paddle. Payload would be one adult, fishing gear and possibly a small kid or big dog.

From there I would like to be able to add width (length of deck tubes) and possibly add pontoons for more carrying capacity. I would consider a small motor for larger configurations but not really interested in anything that would be all that fast.

Key factors would be cost, weight and durability. I envision a custom trailer similar to a canoe trailer full of pontoons, with a box underneath for deck materials and accessories.

I'd like to know if there are plans somewhere for this sort of thing. I've considered different construction techniques:

1. Stitch and glue
2. pvc foam sandwich with fiberglass skin
3. cedar strip or other wood core with fiberglass skin

If somebody has knowledge of plans or a product like this, or ideas for how to proceed, I'd be glad to hear about it.