Random things to do in Vieques:
Bio Bay- It was well worth it though the tour aspect gets tiresome. You paddle out into to bay on kayaks and lounge in the water checking out the gatorade commercial like glowing water. Watch out for the flying fish though one of companions was hit in the head...
Beaches-I went to red, Moon, and green beaches. All had great snorkeling right from the shore, weren't at all crowded and were fun to drive to. Watch out for the spiny little plants at red and green though. Oh an i heard rumors of bullsharks so do your skinny dipping late at night not just after the sun goes down.
Town-didn't do much in the various little towns other than buy construction supplies but the expat bar a block down on the right from the ferry building is supposed to get going pretty well most nights. Feel free to get a hold of me if you have any questions I might be able to answer. Smooches.