Nope. You can anchor in Coral Bay. The National Park Mooring Guide has the no anchor regions marked out. The west side of Coral Bay can be exposed to weather and we've seen boats on the rocks at Sanders Bay after a squall. Hansen Bay on the East End is protected, but its a long dinghy ride to "downtown" Coral Bay. There are moorings on the south side of St. John.

http://www.nps.gov/viis/planyourvisit/upload/MooringGuide.pdf

Cheers, RickG