Propulsion System without Propellers

[seandepagnier]

I think it would be interesting to connect a high power electric motor to the tiller which can then scull the boat propelling it. To allow for more propulsion the rudder size might need to be increased as well.

An interesting aspect is the fact that once motorized the boat essentially has an autopilot, and the same system can be used to generate power (under sail) but slowing the boat down.

The requirement is a computer processor with digital gyroscopes so that rudder movements are made in frequency and time to the waves and boat motion to give propulsion. If fish do it, maybe it is better? At least it would be quieter.

[Fishspearit]

Considering all of the views and no responses yet, I may be the only lunatic on here who agrees with you.

The shaft driven propeller may be the best thing that we have come up with so far, but it requires a lot of energy. Nothing in nature propels itself that way.

The idea of a fin like a fish or whale uses would probably require much less energy, although it will never be able to push a boat at planing speeds. My vague, untested idea that I'd love to model someday is to use a ferrous arm connected to a large flexible fin. An electromagnet and a counter spring to move the short radius back and forth, giving the end of the fin a longer sweeping motion. It could be powered with short electrical pulses to the magnet. The idea being that with short dc electrical pulses it might be able to propel a long,narrow boat at a couple of knots using very little electricity.

Like I said, I'd love to build a small model and see if it works.

[gosstyla]

Ever seen Hobi kayak's fin drive?