Aussie Invention - Canoe Jet

[Big Red]

I know it sounds like something a few guys thought up after a six pack or three. But its true and its real, I just saw it on TV! It is a device that fits into a well in the middle of the (in this case fibreglass) canoe. About 18" high, perhaps 8" wide and maybe 12" long. Inside was a vertically mounted electric motor with a whopping 680 Watts of raw power attached to an impellor and a downward angled (25 deg?) and rearward facing exhaust. The unit did not protrude below the canoe. Weight is 11kg not including the battery. Cost $1200 of our folding.

The show is one where people show their "inventions". The inventors come on and answer a few questions from panel. The lady on the panel asked "If the unit goes through a hole in the bottom of the canoe, how come water doesn't come in?" The answer was that "The unit goes in a well, and that the water level is higher outside the boat than in the well! Its just physics." What the?

[Mike Field]

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Is she that nutty interior design woman, Bluey? She sounds just the sort of person who if, while canoeing, ran a rock through the bottom and let the water in, would smash another hole with the paddle to let it out again.

Sounds quite a nifty invention. I'm rather sorry I missed seeing it.
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[Big Red]

Dunno Mike, I don't usually watch it. A mate rang me up and said there is a machine to make canoes go faster (thats how it was advertised). Not sure about the lady, perhaps she was an interior designer, I think she was there to pretty up the panel But it was the designers that made the stupid comment

I think for the trouble, one of those Minn Kota's would be easier. But something similar could be made from a one of those submersible pumps with the plastic housings. Might be fun to fool around with. Anyone out there mucked around with this?

[JimJ]

I missed it last night due to an Association meeting.

Have a peek at
http://www.abc.net.au/newinventors/txt/s1215153.htm

[Mike Field]

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Hh'mmm. Interesting. I wonder how much of the thrust is wasted by being directed downwards? Or whether it would be worthwhile having a tailpipe project below the keel to direct the flow horizontally? (I saw a similar arrangement on a small boat once where such a tailpipe could swivel, and thereby steer the boat. And now I think about it, isn't this how some PWCs work?)

A mate of mine built a little Minn-Kota into his Scruffie a few years ago, and he said it drove her along in calm water at about one or two knots. Of course, in such an arrangement there is a propellor that projects, which I suppose can't really be avoided. (But then see Para.1 again....)
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[PeterSibley]

I wasn't very impressed,nicely built ,well engineered....it just seem like the wrong solution to the "problem".The idea of having to cut a 250mm square hole in the bottom of your canoe is distressing! If you really need to stop paddling a trolling motor and bracket seems a better way.Easier to reverse too...

[skuthorp]

Didn't see the program, but I've toyed with a few ideas including steam power. At the moment I'm looking at 'marinising' a straight-shaft brush cutter with a small tunnel prop. I'll buy a used one so it doesn't matter if it's no use. Rust and the stuffing gland in the shaft might be the biggest problem!
Even small outboards on a board over the side are to unstable in a Macgreggor, but a poly-pipe outrigger might solve that.

[seafox]

one of my favorite jobs at the topsoil selling site is filling the water truck with a fire hose. if the nozel is in the air their is a lot of force pushing back yet if the nozel is submerged that force goes away.

long winded way to say it is my understanding that jets need to exzust into the air and even then use about twice the horse power as do propellers ( or feathering paddlewheels) doe the same proelling force.

one other thought a pair of side wheels can be clamped on the canoe with out modifieing the hull ( read cutting holes in it) and the wheels can act as outrigger providing stability and even added flotation
jeffery

[seafox]

noted on reading the story that air is added to the water stream so that a propulson force is achived
jeffery

[Paul H]

When I saw the title of the thread, it reminded me of a Canadian that mentioned a friend of his had made a canoe jet, but of an entirely different nature. He'd gotten a jet ski that had been augered in, and morfed the tail end of it, with engine and jet pump to a canoe

I didn't see any pics, but it would be an interesting way to move freight in shallow waters.

[mike from Boston]

Check this out MOKAI.COM

Looks cool, and seems to work.

Mike

[Big Red]

Wow