We snorkeled at the Frenchman’s Cove beach, Magen’s Bay and Lundquist Beach. Each of these areas is mostly sand and sea grass, so you’ll see wandering schools of small fish and maybe a turtle or conch or two. Here are some ways to save money:
1) The snorkeling at these areas is not as interesting as in a reef area so, you could easily share equipment. However, we did not go out toward the point, where it might be rockier and may have more to see.
2). I had brought goggles and a snorkel to save space and did not regret leaving fins home that I would use to cover more ground or protect my feet against rocks. Inexpensive mask/snorkel are available in the store, which you could bring back as souvenirs.
One last point is that the best reef/fish viewing experience we had was at Coral World, which is near Lundquist Beach. Normally entrance fees were $20/adult, but due to Hurricane Maria damage, it was only $10. Their underwater, 360 degree observatory has huge tarpon and jacks, corals, other sea creature in a reef setting with color explanatory exhibits. They did have a “scuba” experience if you want to get wet.
We have always rented a car for the duration of our stay in St. Thomas, but a taxi from the airport works too. There is no shuttle to the Marriott property. Once, the rental car office was closed, so we took a taxi and picked up the rental car at the hotel. I vaguely remember it was around $30 or $40 for the taxi ride.