Through St. Thomas or direct to Beef Island?
I carried regs, camera, mask and a few clothes, checked the rest in a big duffle. Our bags all made it in safely to STT except for one. We moved over to Virgin Gorda that night via private charter (you can do it on the public fast ferries also - it just has to be earlier) and the bag arrived on the ferry the next morning. It's a very efficient way to move between islands. The ferries we saw ran like clockwork. Two of my friends returned a day early so left VG at 8am on the Saturday ferry for a 1pm flight from STT.
Consider taking the Ferry to Virgin Gorda one day, it's a completely different vibe than Tortola, much quieter and imo much more scenic. Snorkel at the Baths and if you have time, eat at Rock Cafe. You can go both ways easily the same day certain days of the week.
If you are flying into STT there's two ferry ports, one downtown and the other on the East End about a 30-45 min shared van ride.
We were through STT and on the van for the East End in about 15mins. In late April. You do have to clear customs/immigration both ways, in our case entering the BVI's was a 10min process and re-entering the U.S. on St. John, equally fast or faster.
The longest line was waiting to check-in in at STT on our return. Especially on Saturday, there's busloads of returning cruisers as Charlotte Amalie is a major cruise port.
Ferry options:
Virgin Islands Ferry Schedule Check to make sure they're currently running before you go, some are seasonal and at least one has gone out of business and is now running again in the last couple of years.