From what i understand Hull Bay is your best bet ( located just west of Magens beach), but it has to be the right time of year and that isn't until October or November. Let me know if you find anywhere with swell and if you can rent a board down there. Good luck
Tortola - Apple Bay & Cane Garden Bay is where its at in the Carribean. I got married in Tortola. Snag some waves in the AM, get married in the PM, Not a bad day. I was there in March & there was a good swell pushing through (chest high). Not sure how it will be in the summer. Probably not too good unless a system pushes in.
I've been to St. Thomas and St. John's and you won't find many waves there without local knowledge of the reefs, a boat, and a big swell but Tortola is where you will find some good, consistent surf. I think September-March is the season for waves there. I was in Tortola for Thanksgiving last year and scored huge. Apple Bay is the most consistent spot, which offered at least waist-chest high waves for us every single day. We scored Cane Garden at a solid 6ft, which was just epic, a reeling right with crystal clear water and a really solid barrel- probably the best waves of my life. Josiah's Bay is the other spot, which is on the other side of the island and was pretty sketchy and breaking big when we were there. If you do go to Tortola make sure and hit up the Full Moon Party at the Bomba Shack... i really can't say enough about this party. It's held at this shack on the beach right at Apple Bay and hundreds of people are there drinking shroom punch, shroom tea, eating shrooms, smoking weed, doing blow... you name it, half-naked women, i mean just everything, without any sort of law whatsoever. Such a sick place. Highly recommended.