We just came back from NCL's trip to Tortola. We did the excursion that took you to the baths. This is an incredible sight NOT to be missed. It's been on the cover of MANY travel magazines. They have an NCL rep. who guides you through the baths but you can slowly fan off without them noticing you. You can buy an underwater disposable camera on-board or get one at your local cvs before you go at a better $ I amagine. 12 dollars at cvs. BRING the camera! TRUST ME!! If you own a snorkle,..bring it as NCL gives you the ones with an open hole and then you get water in it every time you breathe.(they stink)
You get roughly 45 mins. to an hour to snokle and you get back to the ship in time for a quick whirl around town (tortola) to shop so don't worry you will not have anytime to shop. Go past that stupid flea market they have as it is all the same stuff at every table and it is all over priced. Go into town where you can get unique things at better prices.
NOTE: Some passengers also liked the ATV tour as well, but for us we didn't feel one bit like we made a mistake.