Brent":1i751u09 said:
I thought jet drive systems are inefficient esp at slow speeds.
Brent-
They are inefficient at all speeds, wasting about 25% of the H.P. in internal friction of the jet pump.
Plus they are very hard to steer at low speeds, have poor reverse thrust (diverted), and only have steering when you have the motor applying thrust: no thrust = no steering.
Their advantage, though, lies in shallow water use where they require less depth than a prop drive.
Contrary to popular myth, they are not invulnerable to problems picking up gravel, and damage and wear do occur when passing larger particles through them.
River Horse, of course, was a CD-22 Classic, and made it through from the Mississippi river system to the Pacific Coast, if I remember right.
I don't remember, though, if they used a jet drive. Anyone remember?
No doubt, the CD-22 would make a great camping boater-home on the river, as we've already noted many times.
One more thought- the fiberglass cored hull of the C-Dory is very tough, but not a match for a 1/4" thick aluminum alloy river sled for taking on bolders at speed. The aluminum bends, dents, and gets scraped up, but will not suffer major cracking like fiberglass on a severe impact.
Joe.
