This is an archived message posted to the Kayak Building Bulletin Board. If you would like to ask a question about building kayaks, you can post a new message.
I would hate to suggest that we kayakers could use some technology from those hateful jet-skiers, but how about an inboard propeller, mounted in a tube running through a section of the kayak? There would be increased drag forces of the water against the inside wall of this tube, but maybe it would be negligible compared to the losses of a bare prop, where water is free to move sideways. I'm not sure which is more energy-wasteful.
As to efficiency, I think that the fluid losses would be much higher than any mechanical losses in the bicycle-type drive system, making those mechanical losses negligible. I doubt that there is as much as 10% loss in a bicycle drive train, as mentioned below. Think of how easy it is to crank a bike when it's on a repair stand. And how long a bike wheel will spin after you've stopped cranking.
Dean
This is an archived message from The Kayak Building Bulletin Board.
Guillemot Kayak - High
Performance Wooden Sea Kayak Designs
