Ranong Diving: Surin, Richelieu Rock & Koh Phayam Trips

Featured image: Tim Sheerman-Chase, Public domain, via Wikimedia Commons.

Ranong diving at a glance

Treat Ranong province as the northern end of the Andaman side. Boats head out to offshore islands and marine parks, and the day usually starts from Koh Phayam, Koh Chang (Ranong) or the mainland coast. Our Andaman Sea diving overview shows how this stretch fits the wider coast.

• Best for: quiet, low-crowd days on the water, Surin and Richelieu Rock day trips, and budget snorkeling.
• Not ideal for: divers who want many shops, night dives or wreck and tech options.
• Base choice: Koh Phayam or Koh Chang for island time, the mainland coast for Laem Son snorkeling.
• Format: day trip, private charter or an overnight at Surin or Koh Phratong.

Dive and snorkel sites around Ranong

Four areas cover almost every trip. Laem Son National Marine Park headquarters sits at Bang Ben Beach on the mainland, about 60 km south of Ranong town. Its islands include Ko Kum Yai, Kum Noi and Ko Khang Khao, where staghorn and pillar coral shelter marine life. Use the table to match a site to your experience.

Surin Islands and Richelieu Rock day trips

Mu Ko Surin National Park holds two main islands, Ko Surin Nuea in the north and Ko Surin Tai in the south, plus several islets. Sheltered bays on the east side hold the best-known reefs. Richelieu Rock lies within the same marine park area and draws certified divers on long speedboat days. Operators market it as a world-class site and mention whale sharks, but sightings are never guaranteed. Our best Thailand dive sites list shows where it sits nationally. Check Thai National Parks Department pages for park rules.

Koh Phayam, Koh Chang and Laem Son snorkeling bases

Koh Phayam is the usual low-key island base. One dive shop sits at the crossroad on the island, 100 m before the entrance to Ao Yai Bay, the main beach. Boats to Koh Phayam leave daily from the island pier in Ranong town. Koh Chang in Ranong province is a second quiet base for the same day-trip routes. For mainland snorkeling, Bang Ben Beach is the entry point to the Laem Son islands, and overnight camping is possible there.

Day trip, charter or overnight: which fits

A shared day trip is the simplest way to see Surin or Richelieu Rock. A private speedboat charter suits groups, and one operator lists capacity up to 20 people. Some charters run 2 days and 1 night, with a night inside the Surin Islands marine park or on Koh Phratong. Overnights cut the transit time on your second dive day. Day trips suit travelers with a tight schedule. For longer itineraries, our Thailand dive trip planning guide compares formats.

Costs and what's included

Prices below are last published figures, so operators set current rates. In its October 2025 update, Travelfish listed ฿600 per person for a Laem Son snorkel day, with lunch and gear but not the ฿200 park entrance fee. Surin and Richelieu Rock days cost more because of the longer sea legs and fuel. Ask every operator what the quote covers.

• Gear: mask, fins and tanks, or only snorkel kit.
• Meals: lunch and drinking water.
• Transfers: pier or hotel pickups.
• Park fee: usually paid separately from the operator price.
• Insurance: dive cover is your own responsibility.

Best season and park closures

The Andaman monsoon closes or restricts offshore trips for part of the year. Park open and closed dates for Mu Ko Surin and Laem Son change, so read the current notice on the national parks authority site before you book. We list no dates here because none are verified.

Getting there from Bangkok, Phuket and Ranong town

Fly or take a long-distance bus to Ranong town, then continue by road to Bang Ben Beach or to the island pier for Koh Phayam. Operators arrange transfers to their departure points, often near Kuraburi, so ask for pickup details when you book. Current schedules sit with the boat operators and bus companies.

Courses and certification: what to ask operators

Local operators list Refresher, Discover Scuba, PADI Open Water and PADI Advanced Open Water options. Use the PADI dive shop finder to check accreditation, and confirm the instructor's current certification. Ask about group size, depth limits at Richelieu Rock and whether the course needs a separate travel day. Costs vary by shop; see our cost of diving in Thailand breakdown for benchmarks.

Mistakes to avoid and alternatives

Do not assume Ranong town has a dive scene. Do not book Surin without checking the season, and do not skip the park-fee question. Expect no Similan-style infrastructure, and budget for a long travel day if you plan a course. Beginners wanting many shops and departures often do better elsewhere.

• Khao Lak or Phuket: more shops and departures for Surin and Richelieu Rock trips.
• Koh Tao: Gulf-side base for courses; see our Gulf of Thailand diving guide.
• Resort stays: compare bases in our Thailand dive resorts guide.