Welcome to Black Rock
As you will likely be making four dives here there is ample opportunity to explore the site thoroughly. The routes can depend on which direction the current is travelling, where to spot special marine life at certain times of the day and your diving experience and air consumption. The west side of Black Rock is the deepest so it is best to explore this area on the first dive of the day where you can hit your maximum depth of 30m.
Jump in around the middle of the rock’s west face to avoid any strong currents and descend down next to the sheer wall. The wall ends around 24m where there is a rocky plateau. Heading west this plateau then tumbles down to depths around 50m. Keep your eyes peeled for activity in the early morning light.
If there is current you are likely to find more action where the strongest water movement hits the rock, which is usually at the thinner edges of the rock either at the north or south tip. You can approach fairly easily using the rock’s topography for shelter until you get close to the sweet spot. Depending on conditions you can shallow up on the sheer wall checking out all the cracks for moray eels, shrimp, cowrie shells and scorpion fish. If the current takes you round to the east side you can shallow up on the sloping side of the rock. There are plenty of hard and soft corals, sea fans and sea whips on the rock where you sometimes find ornate ghost pipefish and tiger-tail sea horses. In the shallower waters there can be huge schools of fusiliers, smaller schools of batfish and cuttlefish as you ascend for your safety stop.
A large Gorgonian fan coral at Black Rock
For your second dive at Black Rock you could try jumping on the opposite side of the rock, the east facing side. Descend down following the sloping side until it bottoms out at around 22m. If the current allows keep swimming east over the sandy bottom, there are some small clusters of rocks further out covered in sea fans. The bottom slowly descends beyond 30m, no need to go to deep, with good visibility you can swim in mid water and look out for rays resting in the sand, passing eagle rays and barracuda and Spanish mackerel that patrol out in the blue.
By dive three you probably have a fairly good grasp of the site’s topography and interesting areas. Black Rock is not a huge dive site, it’s possible to encircle the entire rock in one dive. So either head to parts you have found the most interesting or explore the remaining areas you might have missed on dives one an two.
Of course all the best dive plans are quickly forgotten when something big swims along. Black Rock is probably your most likely Mergui Archipelago dive site to encounter whale sharks and giant manta rays. Our record to date is 33 individual mantas logged during one days diving there. Dive briefings are likely forgotten as you hover and enjoy the show.
Dive four is likely to be shortly before sunset. This is the time of day when the dive site will be most active. Find a sheltered spot to jump and then head to the current. There is no need to go deep, most of the action will be just below the surface down to around 16m. Schools of fusiliers will be feeding on plankton swept by in the current as these schools will be harried by a variety of predatory fish. The movement of life can be mesmerising as the dispersed schools suddenly ball up closer together as danger approaches.