On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe
wrote:

Now directly couple a motor/generator that consists of a stator
winding employing a high pole count configuration, which allows for
high copper utilization (minimizing energy loss and cost), and a
hollow rotor upon which powerful rare earth permanent magnets are
mounted on the outer circumference coupled to a variable pitch prop
system and you can pump out some serious energy. The city buses that
are using these moters claim they capture 97% of the kinetic energy
developed while stopping.

Regardless of the capture mechanism, even at 100% efficiency, there is
only so much energy in a moving column of water and it is not a big
number when you are moving at sailing speeds. Now if you could get
that same column of water rolling down the side of a 1,000 ft
mountain, that's a whole different story. :-)