On Sep 11, 3:41*pm, wrote:
I know I have discussed this before but i finally got a chance to look
over hydraulic motors. *The idea is to use a gasoline engine inboard
on a boat and transmit the power via hydraulics to a hydraulic motor
that is submerged. *This way you can have great flexibility of tilt
and trim etc. *When we discussed this before, somebody said that
hydraulic motors have poor efficiency but efficiency ratings (rotary
power into hydraulic power) is commonly 75% and some are as high as
95%. *RPM at the output might sound like an issue but I see rpms
listed as high as 2800rpm. *Such a drive would have a very simple
transmission.

Well, Kaplan and Asoc. are doing it on a larger scale, but that might
give you something to look into. Man, thats a big lower end!

http://www.alkaplan.com/drives/