Ralf Dieholt wrote:

... I think submarine cruises are a huge market for the future with
billions of $$$ to earn.

This is old news. Submarines have been cruising the oceans for a very long
time now. You just haven't seen them.

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.home.comcast.net/