Zozos H2O is on beautiful Lovango Island 1 mile away from St John. In the bite of the island is great snorkeling which is very weather protected. There is also great snorkeling behind the island although one needs to check on the rip tides as they can be quite strong sometimes.
Being so close to St John a kayak will get you there however it’s more traditional to power over and tour the USVI waters around St John and St Thomas and save the expensive BVI custom charges. You can also hop onto a ferry especially dedicated from St John and back.