We noticed that St. Thomas offers a UNDER WATER BOB (breathing observation bubble). This is a little underwater scooter that you drive under the water - you are wearing a helmet which helps you breath. I noticed Carnival Destiny now offers this as an excursions called BOSS.
Does anyone know where on St. Thomas you can do this on your own without going thru Carnival?
I know of 2 companies that offer this excusion in St. Thomas - but, both request you book this trip directly through the cruise line. When ships are in port they usually fill up all of their available space. So, if you want to do this one - pay the price and don't wait too long to book. (often sell out)
We went to Coral World (adjacent to Coki Beach), and they have the one where you walk on a path with the helmet... It looked like fun, but by husband is a weenie and wouldn't do it... it was quiet and not a lot of folks around.