Waterjet propulsion

["Morrisson, Richard D" <Richard.Morrisson@PSS.Boeing.com>]

I am a bit surprised that all the discussion about waterjets seems to be
centered around the power output and not the efficiency.  Jetski's have
enormous amounts of horsepower for their respective weights and
therefore can afford to be inefficient.  Power is cheap when you're an
air breather!  50 hp is not out of the question for such craft (the
small ones!) while 5 would be a very large drive motor for a small
personal submersible.  I would be interested to hear what details the
group might have in terms of efficiency for these drives.

R. D. Morrisson