jet powered canoe

As far as it getting swamped, Im looking to run a bilge pump or 2 off the cranking battery in case much water comes in. Also I have a large amount of pourable foam I intend to use around the engine compartment in the back and up front as well. My removeable outriggers should provide adittional stability along with some extra bouyance.

 

It's buoyancy.

 

Yeah, I missed that. Still, power means weight. A 6 hp electric (ETEK motor) can develop three times that in spurts. It (with battery) weighs maybe sixty lbs but can be placed almost anywhere, is ultra-reliable, certainly less money than any gas engine.
Granted, gas weighs (maybe potentially) less but its noisy and it stinks, especially if it's in the middle of the boat.
But I'd choose a smaller electric motor (2 hp and 6hp in spurts) due to cost (motor and controller).
Just knocking around ideas.

 

Weight translates to either greater draft or more hull surface area, either of which is adverse to moving up normally shallow rapids.


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Where can you get small jet drives like the one in the mokai? Someone said the Mokai is just a $300 "kayak" with a $700 motor. Where can I get a jet drive like this for $700. I think a 10-15hp version built into a 10-12 foot rib would be an awesome yacht tender.

Good luck with the jet canoe. Seems like a great project.

 

An extra 100 lbs would sink a 20 sq ft waterplane a bit over an inch. I think.

 

Bonne humeur.

 

I put that, I dont even know if its true thats just what I have read. I have never even seen a mokai in person. On one of my local lakes there is someone that has a rib with an inboar jet but im sure its much larger than 10-15hp since ive seen them doing atleast 30-35mph.

 

I think a jet ski (as abnoxious as they are) may be the solution here.

Fun up, or down, stream!

 

I remember reading about an outboard jet made in Germany right ofter th' war...this used a combusting pulse-jet to create jets of water - essentially a bundle of pipe, the thing had no moving parts other than the fluttering reed valves. Seriously - I have seen the thing advertized.

 

Yeah except fiberglass hauls and rocky rivers don't go well together. I've always wondered why no one has made an aluminum hulled jet ski, I guess it just might not appeal to that many people.

 

You could use kevlar.

 

You could use this

http://en.wikipedia.org/wiki/Pop_pop_boat

Dino

 

put smallest jet-outboard (20hp) on a Grumman sport boat

Wiki says they have been used with up to 25hp!

They are quite light weight.

I looked at one for sale that was unbelievably beaten up. I looked like they hadn't used it as a boat, more like a toboggan down wet rocks. I was amazed the metal could take so many big dents and not split, but it seemed to be holding water tight.

I'm surprised they don't make jet outboards in smaller engines, for shallow water or operation around swimmers.


Would a Mud-Buddy motor do it? It is for mud, not rocks, but seems to protect the prop.
http://for-sale.yakaz.com/grumman-sport-boat-for-sale#lo=4&docid=0007mmtqdr3804ro



The Sport Boat is designed to be rowed, sailed, or powered by an outboard motor, and is among few designs to be fairly efficient at all three. It can also be poled or paddled, but is too wide for efficient paddling. It is manufactured in a fashion similar to an aircraft, made of a stressed skin aluminum, riveted together, and weighs slightly over 110 pounds. In current production, it is rated for 750 pounds capacity and a 5 horsepower (3.7 kW) outboard motor. It can plane with as little as a 3.5 hp motor, and has been used with as much as a 25 hp motor. Moving a lone operator forward to the middle seat enables planing performance over 10 mph with as little as 2.5 hp. Ballasting the bow greatly improves operation under power.

 

The best boat I have ever used for running rapids over the years has been the porta-bote! http://www.porta-bote.com/index.php
It is made of 1/4" polypropylene sheet with and put together with a very forgiving support structure. The combination of the very slick permanently lubricated skin of the material and ability of the structure to deform without damage seems to be the key. It can even be QUIETLY hand dragged without hanging up (even over fairly dry rapids) without suffering gouges. Much less hang up than even white water inflatable rafts...

That being said, under power these are about the most energy wasting craft in open water, because of the energy they absorb when being propelled forward. Even minor waves cause the walls and floor to deform and spring back. Also the quality of construction is generally poor, from my previous experience with older models.

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