Ko Pha-Ngan is stuffed with activities, from diving to trekking, kayaking, snorkelling, swimming and beyond.

Hiking and snorkelling day trips to Ang Thong Marine National Park generally depart from Ko Samui, but tour operators shuttle tourists from here too.

Many larger accommodation options can sort out jet skis and kayaks.

Trekking

Almost 90% of Ko Pha-Ngan is comprised of unspoiled tropical forest, with a whopping 40% protected national park land harbouring an abundance of wildlife. Although much of this forest is not open to exploration, some exhilarating hikes await. If trekking along more isolated areas, make sure you take loads of sunscreen and water.

Popular hikes include the Chalok Lam to Bottle Beach Trek and the hilly hike from Hat Rin to Hat Yuan, Hat Thian and on to Hat Yao (east). The hike up to the Domsila Viewpoint, and beyond, above Nam Tok Phaeng is another excellent hike, don't miss it. From here it's also possible to continue up to Khao Ra, the highest mountain on the island at 625m. Switch your flip-flops for decent walking shoes.

Diving

There’s a more laid-back diving scene on Ko Pha-Ngan than on nearby Ko Tao, but there’s no shortage of professional, competitively priced dive operations with courses from novice to instructor level as well as free-diving.

A drop in Open Water certification prices has also made local rates competitive with Ko Tao. Group sizes tend to be smaller on Ko Pha-Ngan since the island has fewer divers in general. Recommended dive outfits include Haad Yao Divers, Lotus Diving, Chaloklum Diving, and Apnea Koh Pha Ngan for free-diving.

Like the other islands in the Samui Archipelago, Pha-Ngan has several small reefs dispersed around the island. The clear favourite snorkelling spot is Ko Ma, a small island in the northwest connected to Ko Pha-Ngan by a charming sandbar. There are also some rock reefs of interest on the eastern side of the island.

A major perk of diving from Ko Pha-Ngan is the proximity to Sail Rock (Hin Bai), the best dive site in the Gulf of Thailand and a veritable beacon for whale sharks. This large pinnacle lies about 14km north of the island. An abundance of corals and large tropical fish can be seen at depths of 10m to 30m, and there’s a rocky vertical swim-through called The Chimney.

Dive shops on Ko Tao also visit Sail Rock; however, the focus tends to be more on shallow reefs (for newbie divers) and the deep-dive waters at Chumphon Pinnacle. The most popular trips departing from Ko Pha-Ngan are three-site day trips which stop at Chumphon Pinnacle, Sail Rock and one of the other premier sites in the area. These three-stop trips cost from around 3650B to 4000B and include a full lunch. Two-dive trips to Sail Rock will set you back around 2500B to 2800B.