Snorkeling Travel Guide

Yes. Reputable Four Islands and island-hopping operators provide life vests, and with one on you float without any effort and simply look down through the mask, with a guide alongside. Tell the crew you are not a confident swimmer so they stay close, practise breathing through the snorkel in the shallows first, and stick to the calmer stops. Plenty of first-timers snorkel this way every day.

Reef-safe mineral sunscreen, a rash guard or light long-sleeve top, a small dry bag for your phone, cash and documents, and cash in small baht notes for gear, snacks and any park fee. Bring your own mask if you own one, since a fitted mask beats a shared one. Add water, a hat and sunglasses for the boat, and motion-sickness tablets if you are prone to seasickness. Tours supply the snorkel gear itself.

No, tours include a mask, snorkel and usually fins. That said, a mask fitted to your own face is the single biggest upgrade to the day, because shared masks tend to leak and fog. If you own one, bring it. If not, do the fit test on the boat's spare: hold it to your face without the strap, breathe in through your nose, and check it seals on suction alone.

Rub a little baby shampoo or even a smear of spit around the inside of the dry lens before you swim, then rinse once with seawater. Do the fit test first so it seals properly, and keep hair from under the skirt of the mask. A mask that fits and does not fog is the difference between watching fish and constantly stopping to clear water.

Yes, families are common on the day boats and the crews are used to first-timers of every age. Keep children in a life vest and within arm's reach, choose the calmer, shallower stops, and let them try the mask in knee-deep water before the first proper swim. A snug mask, a vest and an unhurried pace are all it takes. Watch small children on the deck and near the boat ladder as well as in the water.

The dry season, roughly November to April, brings the calmest seas and the clearest water, which is why it is the prime window. The May to October southwest monsoon is choppier, has lower visibility and sees the odd tour cancellation. Whatever the season, book the early departure, when the sea is usually flattest and you reach the reef before the day-trip crowds. The snorkelling guide has the full month-by-month season.