Snorkelling in Krabi – the best spots, timing and tips

As a rule: the further out you go, the clearer the water and the livelier the reef. The islands right off Ao Nang are ideal for beginners and families, but you will find the best conditions at Koh Rok and Koh Haa to the south.

Visibility is best in the dry season from roughly November to April, especially on windless days after a few calm days in a row. After heavy rain or wind, water near the coast gets murkier as rivers carry sediment out to sea and waves stir up the bottom.

Time of day counts too: in the morning the sea is usually calmer and the sun is already high enough to light up the reef. At higher water you snorkel more comfortably over shallow reefs with less risk of touching coral.

The biggest risk when snorkelling in Krabi isn’t fish – it’s boats. Never swim in longtail landing zones, stay within sight of your boat and use a life jacket or pool noodle in current. Children and less confident swimmers in particular should always wear a vest.

In shallow water, watch out for sea urchins and sharp rocks – water shoes or full-foot fins protect you. Don’t touch anything you don’t recognise.

Thai marine national parks ban sunscreens with certain ingredients such as oxybenzone. Even better than any cream is a UV shirt (rash guard): it protects your back and shoulders, which spend hours in the sun while snorkelling, and doesn’t harm the reef.

Never stand on coral, don’t feed fish and don’t take shells. Swim calmly and horizontally and you will see more anyway – fish flee less from relaxed snorkellers.

Beginners and families are well served by the Poda group and Hong. If you are experienced and want the clearest water, plan a full day to Koh Rok and Koh Haa – in the season from roughly November to April.

A perfect snorkelling day has breaks. Shallow, calm beaches are best for relaxed swimming: the Tup sandbar at low tide, Koh Lao Lading between its rock walls, or a quiet beach like Koh Nok in Phang Nga Bay. Shade is usually under the trees at the back of the beach or along the cliffs in the morning or afternoon.

On a private boat you can take your breaks wherever nobody else is – with cold drinks, fruit and time to simply float in the water.