Many of the gorgeous homes on Water Island were available for short-term rentals, as there are no hotels. On the eastern side of the island is Sprat Bay, a gated community and a US Interior Dept. nature preserve, so we couldn't take the golf cart through there.
Sprat Bay.
There is also a private beach here, but as all beaches in the USVI are public when approached from the water, you could definitely go there by boat. But even on such a small island there are a multitude of beautiful and empty public beaches, so no need for a boat.
Honeymoon Beach.
Then we headed down to the beautiful and not-crowded Honeymoon Beach. There we basked in the sun for a while, playing with our son in the sand or going for bracing dips in the somewhat cool water (it was March). As this beach is the most popular, due to its convenience to the ferry, there were some other beach-goers around but not too many to be bothersome at all.