Best DIY excursion - 12 & 14 yr old w/parents

We are only in Tortola from 7-3 coming up on the NCL Escape and we are looking for a family friendly excursion to do. The kids are 12 & 14. My husband & I were just there in November and we went to Cane Garden beach for the day & drank. Well kind of not wanting to just get drunk with the kids with us this time! Lol

So any recommendations would be great :))

Is there an excursion to Jost Van Dyke offered through the ship? Mainly a beach bar beach, but the kids would enjoy Seddie's magic tricks while you enjoy his Bushwacker or a Painkiller from the Soggy $ Bar.

Another is a taxi to Trellis Bay and the free ferry to Marina Cay (Google that).

For a beach either Brewers Bay or Long Bay (West End) -

http://boards.cruisecritic.com/showthread.php?t=2451323