Been working on St. T since July. Yes, there are attitudes, mostly I feel safe being a woman and alone. I'm also not stupid and stay out of certain areas day and night. St. John is lovely, far far nice. Very common to take the ferry from Red Hook over after work for dinner or drinks. Little isolated, off the beaten track and the roads on both islands scare me (blind curves, angles, switchbacks, drop offs). Like paved goat paths. Snorkeling is good - Waterlemon Cay is a favorite, bring water/snacks and wear sneakers for the 1/2 mile walk, it is over some rough rock patches. Do snorkel across the channel and around the rock. I also enjoy Trunk Bay for a day. Nice amenities - baths and showers all for couple bucks admission. The snorkel trail is pretty cool. Initially I thought touristy, but no. We've been in bait balls of silversides with big tarpon and jacks cruising below and cutting through. Awesome to watch. Found rays 20 feet offshore.
The diving I've done so far is pretty underwhelming. Mostly shallow, 60 foot, patch coral, stock marine critters but nothing in excess or exciting. Yes, the 6 foot Carib Reef shark at Ledges was sweet, the turtle nice, but they are 1 offs rather than typical. It isn't 100 foot walls or pinnacles like Cayman or Saba or 80 minute shore dives in Bonaire. That said I'm sure there is better diving, but working all week I have limited time and no friends who dive. Trying to figure out how I can get over to dive the Rhone.
Did an island hop with friends a couple weeks back - The Baths at Virgin Gorda, lunch in Tortola, snorkel at Monkey Point (Guana Island), sun and drinks at Jost van Dyke (Soggy Dollar Bar). It gets crowded on weekends, but mid-weeks are quiet. Do remember to bring your passport! While St. Thomas and John do not require them, the BVI's do.