Dive site · access from Mergui Archipelago
Western Rocky
The tunnel is the draw and it is an overhead environment — a torch and good buoyancy matter.
- Depth
- 5–40m
- Current
- Moderate
- Minimum level
- Advanced open water
- Access
- Boat
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The case for it
Why dive here
- A tunnel running through the main rock, historically holding tawny nurse sharks up to about 3m
- One of the southernmost Mergui sites, usually dived early or late in an itinerary
- Lobsters, morays, cuttlefish and schooling trevally on the surrounding boulder slopes
Check before booking
What may rule it out
- Advanced open water certification is the stated minimum.
- Moderate current can affect whether the site is suitable on the day.
Access and timing
Plan this through Mergui Archipelago
Best overall months: Dec, Jan, Feb, Mar, Apr. Check the destination planner for operating season, wildlife and other matching sites.
Wildlife
Seen around Mergui Archipelago
rareoccasionalcommonly seenpeak seasondestination closed
These are destination-level records, not confirmed sightings at Western Rocky.
Giant oceanic manta ray
| Month | Likelihood |
|---|---|
| January | occasional |
| February | peak season |
| March | peak season |
| April | occasional |
| May | occasional |
| June | destination closed |
| July | destination closed |
| August | destination closed |
| September | destination closed |
| October | destination closed |
| November | rare |
| December | rare |
Whale shark
| Month | Likelihood |
|---|---|
| January | rare |
| February | rare |
| March | rare |
| April | rare |
| May | rare |
| June | destination closed |
| July | destination closed |
| August | destination closed |
| September | destination closed |
| October | destination closed |
| November | rare |
| December | rare |
Bentfin devil ray
| Month | Likelihood |
|---|---|
| January | rare |
| February | occasional |
| March | occasional |
| April | rare |
| May | rare |
| June | destination closed |
| July | destination closed |
| August | destination closed |
| September | destination closed |
| October | destination closed |
| November | rare |
| December | rare |
Grey reef shark
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | destination closed |
| July | destination closed |
| August | destination closed |
| September | destination closed |
| October | destination closed |
| November | occasional |
| December | occasional |
Indo-Pacific Leopard Shark (Zebra Shark)
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | destination closed |
| July | destination closed |
| August | destination closed |
| September | destination closed |
| October | destination closed |
| November | occasional |
| December | occasional |
Nearby alternatives
Compare another site
Sources & last checked
Checked August 2026
Research is source-backed, but conditions and fees should still be confirmed locally.
View 2 sources and checking notes
- Diving in Burma (Myanmar) - Mergui Archipelago, Dive The World
- The Mergui Archipelago, The Smiling Seahorse
Note on the data: Coordinates are approximate; not surveyed dive-site GPS.