The Galapagos Islands are nice, been 20yrs since I was there but since it is so heavily protected I imagine it is still pretty much unspoiled (although eco-tourism has undoubtedly grown since then).

Tanzania is a nice place to sail as well if you are planning on doing an adventure.
There is a great regatta every year which combines a RAID with some bouy racing:
http://www.tanzacat.com/