May 15
Diving the Myeik Archipelago vs. Thailand's Similan Islands: Which Is Better?
A detailed comparison of two of Asia’s greatest dive destinations — including why Black Rock in the Myeik Archipelago is one of the Andaman Sea’s finest sites, and how Wa Ale Resort is the only land-based resort with direct access.
Two of Asia’s Greatest Dive Destinations
Thailand’s Similan Islands and Myanmar’s Myeik Archipelago sit barely a few hours apart by sea, yet they offer two fundamentally different diving experiences.
The Similans are a polished, well-documented destination — nine granite islands in a national marine park, with reliable visibility, established dive sites, and a steady stream of liveaboards departing Phuket each season. They’ve earned their reputation as Thailand’s top dive destination, and that reputation is deserved.
The Myeik Archipelago — also called the Mergui Archipelago — is something else entirely. More than 800 islands scattered across Myanmar’s Andaman Sea, the vast majority unexplored, with dive sites that scientists are still discovering. This is not a polished destination. It’s a frontier. For serious divers, that distinction matters enormously.
The Similan Islands: Thailand’s Most Famous Dive Destination
The Similan Islands National Marine Park covers nine primary islands plus Koh Bon, Koh Tachai, and Richelieu Rock — widely regarded as Thailand’s single best dive site. Granite boulders the size of houses create dramatic underwater canyons at sites like Elephant Head Rock. Richelieu Rock is a magnet for whale sharks during peak season, and Koh Bon draws manta rays.
Visibility routinely reaches 20–30 metres in the dry season. The catch: the Similans are one of Thailand’s most visited marine areas. During peak season, popular sites see dozens of dive boats simultaneously. New 2026 regulations limiting where boats can anchor reflect the mounting pressure on the reef. The Similans remain exceptional — but “exceptional and crowded” describes them accurately.
The Myeik Archipelago: Asia’s Last Great Diving Frontier
The Myeik Archipelago stretches for several hundred kilometres along Myanmar’s southern coastline — more than 800 islands, most uninhabited, most uncharted underwater. The coral reefs here are among the healthiest in the entire Andaman region. Protected by Lampi Marine National Park, the underwater landscapes show a vitality that overfished and over-dived reefs cannot sustain. Fan corals grow in towering formations. Macro subjects — ornate ghost pipefish, frogfish, cuttlefish, scorpionfish — occupy every nook of the limestone topography.
Widely regarded as one of the greatest dive sites in the entire Andaman Sea, Black Rock is one of the handful of places in the world where giant oceanic manta rays are reliably present — with wingspans reaching four to five metres. The Marine Megafauna Foundation conducts annual research expeditions here. Juvenile whale sharks appear regularly. North Twin is another known hotspot for oceanic manta ray and whale shark encounters.
Wa Ale Resort is the only land-based resort with direct day-boat access to Black Rock. Liveaboard boats also visit the site, but Wa Ale is the only place where you can sleep in a private villa and depart for Black Rock by day boat — no multi-day boat trip required.
Marine Life: What You’ll Actually See
Similan Islands
Reef sharks (whitetip and blacktip)
Whale sharks (primarily Richelieu Rock, January–April)
Manta rays (Koh Bon — hit or miss in recent seasons)
Seahorses and harlequin shrimp
Schools of yellow snapper and glassfish
Leopard sharks on sandy slopes
Turtles throughout the park
Myeik Archipelago
Giant oceanic manta rays (Black Rock and North Twin — among the most reliable sightings in the region)
Whale sharks (Black Rock, North Twin, and open water sites)
Leopard sharks, ornate ghost pipefish, frogfish, cuttlefish, octopus, devil scorpionfish
Enormous fan corals hosting pygmy seahorses
Reef fish in extraordinary abundance across undisturbed reefs
Dive Sites Compared
Similan Islands
Richelieu Rock — Thailand’s most celebrated dive site. Exceptional diversity, regular whale shark encounters during season.
Elephant Head Rock — Massive granite boulders creating dramatic swimthroughs and canyons.
Koh Bon — Famous manta ray cleaning station, though sightings have become less consistent in recent years.
Myeik Archipelago
Black Rock — One of the greatest dive sites in the Andaman Sea. Sheer limestone walls dropping to 20 metres, giant oceanic manta rays, whale sharks. Accessible via liveaboard or through Wa Ale — the only land-based resort with direct day-boat access.
North Twin — Deep-water site and a known hotspot for giant oceanic manta ray encounters.
Canyon Cove — Dramatic underwater canyon with dense soft coral and abundant reef fish.
Coral Garden — Shallow reef ideal for newer divers; exceptional coral health.
Shark Cave — Named for the leopard sharks and whitetips that congregate in its overhangs.
Fan Forest Pinnacle — Dozens of enormous fan corals with pygmy seahorses in residence.
Crowds and Experience Quality
During Similan season, the park sees thousands of divers each week. Popular sites host 20 or more dive boats simultaneously. The Myeik offers the opposite — it’s common to spend an entire day diving with no other boats in sight. Sites within Lampi Marine National Park see so few divers that the marine life shows no sign of human habituation. The Myeik is a better version of what the Similans used to offer before they became famous.
Seasons and Visibility
Similan Islands
Open season: Mid-October to mid-May
Best visibility: November–April (20–30m)
Water temperature: 27–29°C
Myeik Archipelago
Open season: November–April
Best visibility: December–March (20–25m)
Water temperature: 25–28°C
Peak season: January–March for manta ray and whale shark encounters
How to Access Each Destination
Similan Islands
Fly to Phuket — day trip or liveaboard from Khao Lak. No special permits required.
Myeik Archipelago
Fly Bangkok to Kawthaung, or cross the Thai–Myanmar border from Ranong
From Wa Ale Resort, all dive sites accessed by day boat
Myanmar special entry permit required — Wa Ale handles all logistics
Side-by-Side Comparison
Similan Islands | Myeik Archipelago | |
|---|---|---|
Crowd level | High (peak season) | Very low |
Visibility | 20–30m | 15–25m |
Manta rays | Possible (Koh Bon) | Reliable (Black Rock and North Twin) |
Whale sharks | Seasonal (Richelieu Rock) | Present (Black Rock, North Twin, open water) |
Coral health | Good; under pressure | Outstanding; largely pristine |
Season | Oct–May | Nov–Apr |
Best for | First-time regional divers | Experienced divers seeking uncrowded, wild diving |
Unique advantage | Richelieu Rock; easy access from Phuket | Black Rock; only land-based access via Wa Ale |
Which Is Right for You?
Choose the Similan Islands if:
You’re diving Southeast Asia for the first time
You want multiple iconic sites on a single liveaboard
Whale shark encounters at Richelieu Rock are your priority
Choose the Myeik Archipelago if:
You’ve dived the Similans and want somewhere genuinely different
Diving completely uncrowded, pristine reefs matters to you
Giant oceanic manta ray encounters are on your bucket list
You want your dive trip to feel like exploration, not a tour
Diving the Myeik from Wa Ale Resort
Wa Ale Resort is the only land-based resort with direct day-boat access to Black Rock — and it sits inside Lampi Marine National Park, one of Myanmar’s most protected marine environments. Ranked #3 in the Condé Nast Traveller UK Readers’ Choice Awards for Resorts in Rest of Asia, Wa Ale offers day-boat access to Canyon Cove, Coral Garden, Shark Cave, North Twin, and Black Rock itself.
This is a fundamentally different experience from a liveaboard. Guests stay in a private beach villa or treetop den, sleep in their own bed each night, and head out to world-class dive sites each morning with an expert guide. No shared bunk rooms. No compromise on comfort.
For newer divers, the house reef and guided reef dives within Lampi National Park offer an exceptional introduction to Myeik’s underwater world. For experienced divers, Black Rock and North Twin are among the most rewarding sites in all of Southeast Asia — and Wa Ale is the only land-based resort that can take you there.
Black Rock is accessible by liveaboard — but if you want the comfort of your own private villa with day-boat access to one of the Andaman Sea’s greatest dive sites, Wa Ale is the only option.
Ready to plan your trip? Contact the Wa Ale team to discuss dive packages and availability.
