Koh Samui Dive Sites: Sail Rock, Koh Tao & Ang Thong Compared

Featured image: octal, CC BY 2.0, via Flickr.

The short answer: where you actually dive from Koh Samui

Four trips cover nearly every plan. Each runs as a full day of about 8 hours with 2 dives, based on one operator's listing. Pick by certification first, then by which days you are free. Depth limits and transfer times separate the options more than scenery does.

• Comfortable at shallower depths: Ang Thong Marine Park, listed to 20 m and running daily.
• Open Water with some logged dives: Sail Rock or Koh Tao, both listed to 30 m.
• Advanced certification: Chumphon Pinnacle, labelled advanced.
• No certification: a Discover Scuba trip or a snorkel day instead.

Koh Samui dive sites compared

One operator lists the trips below, with prices checked November 2026. Treat the fares as starting points, not market rates.

Sail Rock: granite pinnacle and chimney swim-through

Sail Rock, also called Hin Bai, is a granite pinnacle in the Gulf of Thailand. Barracuda and trevally are the regulars. Whale sharks appear occasionally, but no operator can promise one. Divers also come for the chimney swim-through. One operator lists 2 dives to 30 m, from ฿4,650 per person. Trips run Tuesday, Wednesday, Friday and Sunday. Our whale shark odds guide explains what to expect.

Koh Tao: reefs about 90 minutes away

Koh Tao sits about 90 minutes from Koh Samui, per one operator. Day trips run Monday, Thursday and Saturday with 2 dives to 30 m. Fares start at ฿4,950 per person. Shark Island is one of the sites divers associate with the island. Ask which sites the boat plans to dive that day. A 90-minute crossing is long for anyone prone to seasickness. Sea state matters here, so read our diving season notes before choosing a date.

Chumphon Pinnacle: the advanced option

Chumphon Pinnacle is the advanced pick of the four. One operator describes a granite pinnacle with pink anemones and schooling fish. Whale sharks are a chance, not a promise. Trips run Monday, Thursday and Saturday, with 2 dives to 30 m from ฿5,150 per person. Advanced Open Water is the usual certification for that depth. Our guide to PADI course options shows how to get there.

Ang Thong Marine Park: shallow and daily

Ang Thong National Marine Park spans 42 islands with limestone cliffs and coral. Diving here is the shallowest of the four, with a listed maximum of 20 m. Trips run daily from ฿4,800 per person. That makes it the easiest day to fit around a flexible schedule. Park rules and fees come from the national parks authority. A snorkel version also runs daily, with price on request.

How to choose: level, days free, budget, and sea conditions

Start with certification. Open Water divers are generally limited to 18 m, while the listings above quote 30 m. Ask any operator how it handles that gap. The PADI course levels explain each step. Next, check your calendar. Sail Rock runs on different days from Koh Tao and Chumphon, so a free Monday rules out Sail Rock. Fares across the four span only ฿4,650 to ฿5,150, so budget rarely decides it. For comfort, check the water temperature before picking a wetsuit. Then see what you might spot in our marine life guide.

• Booking a day the trip does not run, such as Sail Rock on a Monday.
• Choosing Chumphon Pinnacle without advanced certification.
• Expecting a whale shark on a given day.
• Underestimating the 90-minute Koh Tao crossing.

Costs and what to confirm before booking

One operator lists a deposit of 20% of the fare. That is ฿930 for Sail Rock, ฿990 for Koh Tao, ฿1,030 for Chumphon Pinnacle and ฿960 for Ang Thong. The listing does not say what each fare includes, so ask before paying. Compare operators using our guide to choosing a dive operator.

• Gear rental, lunch and park fees: included or extra.
• Hotel pickup and the departure pier.
• Refund or rebooking policy if weather cancels the trip.
• Minimum certification the operator requires for your chosen site.

Snorkeling and private charter alternatives

Snorkelers have two options. Koh Tao snorkel trips run Monday, Thursday and Saturday from ฿2,650 per person. Ang Thong snorkel trips run daily, with price on request. Both are full days of about 8 hours, which suits mixed groups of divers and non-divers. Private charters start from ฿35,000 per boat for 2 dives to 30 m on a flexible full day. The deposit starts at ฿10,500. If 8 divers split it, that is about ฿4,375 each. No certification at all? Book a Discover Scuba trip instead of an open-water site.