To the best of my knowledge there is no "sanctioned" cliff diving here but if you google, "cliff diving st thomas usvi" you'll find a couple of youtube links and some links to other vague information which may or may not be of help. You can zipline on STT if that's of interest at Tree Limin' Extreme on the North side of the island!

It can be extremely dangerous, especially when the ground seas are up, during the winter months. Quite a few people over the years have lost their lives being swept off the rocks and out to sea. These are remote areas so the chance of getting help, quickly, in an emergency are remote and time consuming as well. Not to mention, one has to be careful of sea urchins, getting out of water and rip tides while in the water. Do the zip line adventure and call it a day. Be safe.