Amphibious, Moped Powered, Mini Pontoon Boat.

I'm planning out a boat i'm about to make to go down the last 190 miles or so of the hudson river with a flotilla of giant art boat raft things made out of garbage. I would not be riding the whole thing, a bunch of time would be spent with it lashed to the side of a larger raft. It would be used more for excursions and off shoot trips of different kinds - a totally amazing amphibious skiff.

The boat would be as follows: A moped powered pontoon boat where you can scoot up on land and ride off into the distance, come back to the boat, strap on the moped and whiz off down the river. The goal here is for it to be more like a jet ski than a boat really. Non-destructively attaching the moped to the float to power the sucker and then detaching it for outings of one kind or another.

My current idea is to build a couple of reinforced foam pontoons connected with a platform, and on that platform is a stand built to support the moped/lock it down. The back wheel is set on a pair of free spinning rollers, those rollers would alternately power a prop, so by driving the moped the prop spins etc. The rudder would alternately be controlled by turning the moped handle bars (TBD).

If the moped ran out of gas, you could just pedal right along, which would be a nice plus, and once you hit shore, you could just moped on into town, or wherever you were going.

My first question is whether the moped will be able to spin a prop fast enough to move the boat. This one goes about 25mph on flat land, while carying 200lbs. is the resistance of the water too much to work against? Would some kind of paddle wheel be more appropriate? Would it have to be direct drive to work properly?

Also, is pontoons the way to go? or is there a more appropriate boat style to consider?

Also, how big should the pontoons be, and will reinforced foam pontoons do the trick?

Will a pontoon boat be too tippy and just shuck the whole situation into the water?

I have also though that it would be pretty amazing if the pontoons had wheels attached to the topside, so once you get on land you just flip it over, lash it to the rear of the moped and tow it to your next body of water and continue to meander. But that would have to come a bit down the road....

So What am I missing... is this way more unfeasible than it seems. Hard yes, clearly. But maybe, just maybe, it would be totally amazing.

Thoughts?

 

Ahem:

 

Yes!!

Perfect! This shows a paddle wheel, at the higher speeds of the back wheel attainable with the moped - 25mph+ easily would a prop be better do you think?

 

Screw propellers are just a passing fad - the novelty will soon wear off.

My own guess is that your moped (or motorized bicycle, it sounds more like) will be powered by a tiny engine. Sure, a prop will work, but in a flotilla of artsy-fartsy boats, what will people notice and remember?

 

Ok, if you insist:

 

Rick Willoughy is the expert on getting power into the water from pedals.

He has at least half a dozen pedal powered boats (he uses the new-fangled screw technology) , and I have personally seen one of them do nearly 18 knots.

I am sure he could provide a few good suggestions.

 

Shuttlebike Amphibious bicycle

Have you seen this:
http://www.gizmag.com/go/2505/
It has some interesting features, like the handlebars steering the boat and it has inflatable pontoons so it easily pack up and ride on land with the boat components collapsed.

 

Haha! Very clever!