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On Fri, 04 Jan 2008 20:14:09 -0800, Gordon wrote:

Any recommendations?
Gordon

Think about it this way. If the generator is 100% efficient, then to
generate 746 watts, one horsepower must be provided. Imagine a dinghy
with a one hp engine pulling your boat backwards and you get a sense
of practicality. In practice, two or three hp is probably closer to
what the effect might be.

So there is plainly an upper limit to the amount of power a towed
generator can realistically provide to a small sailboat.

Chuck
S/V Sans Serif

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In the late seventy Yves Gélinas "Jean-du-Sud around the World" used a towed
generator.
The electrical power produced was mainly used to communicate on his short
wave radio.
Every day he radioed his position. Then all of a sudden no more
communication were transmitted by him.
Later it was learned that the impeller on his towed generator had been
chewed to pieces.
When he returned home I talked to him and he stated that the sharks made a
meal of the generator impeller.
He also mentioned that the life expectancy of an impeller is in relation
with which region of the globe you are sailing.

In article , wrote:
In the late seventy Yves Gélinas "Jean-du-Sud around the World" used a towed
generator.
The electrical power produced was mainly used to communicate on his short
wave radio.
Every day he radioed his position. Then all of a sudden no more
communication were transmitted by him.
Later it was learned that the impeller on his towed generator had been
chewed to pieces.
When he returned home I talked to him and he stated that the sharks made a
meal of the generator impeller.
He also mentioned that the life expectancy of an impeller is in relation
with which region of the globe you are sailing.

Unless the impeller is perfectly balanced there'll be some 'wobble' and
therefore vibration. I wonder if this is similar to the 'creature in
destress' vibrations that sharks pick up? ... maybe someone could patent
this as a lure for shark fishermen!

Justin.

--
Justin C, by the sea.

Towed generators are practical for working sailboats. It is free
energy and they have usable output.

BUT.

1. Most sail boats spend over 95% of their time at a dock or at
anchor. The towed generator is useless then.
2. If you are motoring it is an extremely expensive and inefficient
way of generating power. Put an extra alternator on your engine and
gain a 500% increase in efficiency and a fraction of the installation
and maintenance cost.