One tidbit ... There are two Cays south of Puerto Real on the south shore of Vieques. One might be tempted (I was) to sail in between them and anchor off the old broken-down dock. The water is pretty shallow in there.

The preferred anchorage is just west of the sandbar to the North side of the western Cay. There is sea-grass here and I have been told that getting an anchor to set can be difficult. I have been lucky because we've been there twice and gotten the anchor to stick both times. Esperanza is a beautiful little town with lots of places to eat and some shopping. Makes a nice stop if you plan to visit the Bio-Bay. (Hopefully it will be back to full strength soon!). The big shopping 'mecca' on Vieques is the town of Isabella Secunda on the north-shore, which you can access by micro-bus for $4 during the day, and $6 at night. Buses run almost continuously. There's a nice dive shop and an pretty decent supermarket.