I saw them at the Gold Coast boat show a couple of months ago and thought about buying one and getting the wife to wind the handle, then thought I am better off with my old Yammie 3, at least it does not argue back when you want to go faster.
Should stick a motor on it
I have a couple of electric 12v motors with reduction boxes that would suit.
Good idea but noisy. I intend to use the long shaft and Korts nozzle but a larger propeller turning slowly. I had a play with one of the motors today, think it's a wheelchair motor. Shaft rotates about 200rpm with heaps of torque.
I'd suggest getting something better than my "Cash converters" whipper snipper to drive it... Otherwise you'd expend more energy trying to start the bstrd compared to the handle version above!
I've sworn more at that f**n whipper snipper than any other device I own.
I have a single cylinder air cooled Chinese diesel available that I was going to convert my tender into a long tail. It is a bit heavy but the main draw back would be noise. I think an electric long tail is the go but with a frame and Korts nozzle. I think you would be instantly unpopular if you used a whipper snipper motor!
The hand version is hopeless. Rowing is a wonderful exercise because it uses a large number of muscle groups. Turning a handle is very low power as well as an awkward position. Any breeze and you would be blown backwards in no time.
Years ago I seen a guy in a suit with a brief case crossing sydney harbour weaving in and out of the ferries on a push bike attatched to two poontons he was doing about 6 knots it was unreal!
http://www.aaametalsuppliers.com.au/stainless_marine_fittings/stainless_whippella.html
www.whippella.com.au/applications.html