After that little incident, he stayed on the left side of the road. If you plan to do a lot of snorkeling, then you should purchase a snorkel and mask at home before you leave on your trip rather than renting them in the islands. Some resorts furnish them, however, it's always best to have your own. Go to a dive shop and have them help you find a mask that fits. Any brand will do, however, I like the kind that keep the water from washing down the top if we hit a wave.
Hubby uses a plain, cheap snorkel and is perfectly happy.
If you are staying at a resort that furnishes fins, then to save weight and space in your suitcase, use the resort ones. I prefer fins with back straps that must be worn with scuba booties. My fins are the shortest ones I could find so that they will fit in my duffle carry-on bag. I.D. Residents of other countries need a passport. Alas, detailed travel books about St. Vincent and the Grenadines are far and few between.