Stumbled across this today - never knew they were what they were
called though.

http://en.wikipedia.org/wiki/Flettner_ship

Some different designs - some actually have been built.

http://gcaptain.com/maritime/blog/oc...-ship-designs/

I wonder if I could try this on the Ranger. Might be fun. Need to
find a cheap parasail though.

http://www.youtube.com/watch?v=SdJRxm0hiTY

Obligatory fishing video.

http://www.youtube.com/watch?v=sA-4wcaRM9w