Surin Islands Liveaboard: Richelieu Rock, Season & Tips

Featured image: Kent Wang, CC BY-SA 2.0, via Flickr.

Surin Islands liveaboard: the short answer

Surin rarely runs as a standalone trip. Operators in Khao Lak and Phuket bundle it with the Similans on itineraries of about 3 to 5 nights. Richelieu Rock is the headline site, a horseshoe-shaped limestone pinnacle roughly 16 km east of the islands. Mu Ko Surin National Marine Park sits near the Myanmar border and was declared in 1981. Expect the park to be closed from about mid-May to mid-October. Divers with Advanced Open Water who like big schools and macro life get the most from it.

• Good fit: certified divers with some logged dives who want Richelieu Rock.
• Good fit: divers happy to spend 3 to 5 nights aboard a boat.
• Weaker fit: Open Water-only divers who want to avoid depth.
• Weaker fit: anyone planning to travel between mid-May and mid-October.

What the Surin Islands are (and what you actually dive)

Five islands make up the park: Surin Nuea (North), Surin Tai (South), Koh Ri, Koh Kai and Koh Klang. Granite boulders form the west-side dive sites. Shallow sloping reefs run along the east side, and the coral gardens suit snorkelers. Surin Nuea has a ranger station and bungalows for overnight stays on land. Around 150 Moken, a sea-nomad people also called Chao Leh, live in two small communities on the islands. Some boats arrange a village visit during a surface interval. Treat it as a visit to someone's home. Ask before taking photos and follow your guide's lead.

Surin vs Similan vs Koh Bon and Tachai: which suits you

Surin lies about 103 km off Khao Lak and roughly 88 km north of the Similans. Distances vary slightly by source, so treat them as approximate. Each area has a different character, which is why most trips combine them. Our guide to Similan liveaboards covers the southern half of that route in detail.

Richelieu Rock: who it suits and what to check

Richelieu Rock is almost entirely underwater. At low tide only about 1 m of rock breaks the surface. Maximum depth is around 35 m, which is beyond the 30 m limit of Advanced Open Water. Most dive sites in the two parks start at 5 m and go down to about 30 m. Open Water divers should upgrade before the trip. PADI course options include the Adventure Deep Dive, which some operators run during the trip itself. Visibility is reported at 15 to 50 m, and many sources put it at 20 to 30 m from November to April. Water temperature is around 27 to 29°C. Pinnacles can bring current, so ask the guide for a site briefing. Whale sharks and mantas pass through at times, but sightings are never guaranteed.

• Hold Advanced Open Water or equivalent.
• Log enough recent dives to feel calm in current.
• Bring a surface marker buoy if your operator requires one.
• Ask whether Richelieu is on the itinerary, not just the Surin area.

3-night vs 5-night vs longer trips

Trip length decides how much you see. One Khao Lak operator lists a 3-night trip with 10 dives and a 5-night trip with 18 dives. Both include Richelieu Rock. Short trips usually squeeze the Similans, Koh Bon or Koh Tachai into fewer stops, so some sites get skipped. Longer routes leave time for island stops and a Moken village visit. For a longer or more remote route, look at Mergui trips into Myanmar. Shark-focused divers can also read about Burma Banks shark dives.

• Choose 3 nights if time is tight and Richelieu is the priority.
• Choose 5 nights if you want Surin sites and Richelieu in one trip.

Liveaboard or Khao Lak day trip?

Day trips to Surin run from Khao Lak. Islands sit about 103 km offshore, so much of the day goes to sea transit. A day trip fits fewer dives and fewer sites than the 10 to 18 dives on a liveaboard. Richelieu Rock is several hours from land, which is why divers favor sleeping aboard. Day trips suit short stays or travelers unsure about boat life. Liveaboards suit divers who want several Richelieu dives at different tides and light. Compare departure times and dive counts with each operator.

When to go and when the park is closed

The park is open from about mid-October to mid-May and closed during the monsoon. November to April is the calmest stretch, with visibility often 25 to 30 m. Whale sharks are most often reported from February to April. Some islands also close on a rotation inside the open season, and daily visitor limits apply. Dates move from year to year. Thailand's national parks department publishes the current opening dates and closures.

Costs and what's included

Published trip prices vary by operator and season, so request a written quote. Trip length is the biggest driver. Boats range from backpacker-style to luxury, and cabin type moves the price within each. Park fees are charged to guests on many boats. Ask whether the fee is paid aboard, since it may sit outside the quoted price.

• Boat tier and cabin type.
• Trip length and number of dives.
• National park fee, and whether it is paid on board.
• Gear rental and nitrox.
• Airport or hotel transfers.
• Insurance. Divers Alert Network offers short-term dive insurance.

Getting there: Khao Lak vs Phuket departures

Boats depart from Khao Lak or Phuket, usually in the evening. You sleep aboard and wake up in the park. Phuket airport is about 1.5 hours from Khao Lak. Many operators include a transfer from the airport or a hotel. Others charge extra. Our guide to Phuket departures covers that side of the route. Book a flight that lands well before the evening boarding time.

Choosing a boat and operator: questions to ask

Group size and guide ratio shape your dives more than the boat's age. As one example, a Khao Lak boat caps at 20 divers with 4 divers per guide. Use it as a benchmark when you compare quotes. Our liveaboard boat comparison helps narrow the field.

• Is Richelieu Rock on this itinerary?
• How many divers, and how many per guide?
• Is nitrox available, and at what cost?
• Is the park fee included?
• What safety equipment is aboard?
• What are the cancellation terms?

Common mistakes to avoid

Most problems come from mismatched expectations, not from the dive sites.

• Booking a short trip and expecting Richelieu plus every Similan site.
• Assuming the sea is open year-round.
• Not checking whether the park fee is included.
• Booking Open Water-only divers onto deep-focused itineraries.
• Counting on a manta or whale shark sighting.