Black Rock

Black Rock is the reason Mergui itineraries point north: a solitary outcrop hours from anything, where oceanic manta rays arrive through the season's core months to be cleaned and to barrel-feed when the plankton thickens. Divers hold the boulder slopes while animals spanning several meters bank overhead, sometimes in relays for an entire dive. Marbled rays pile under the ledges like stacked dinner plates, cuttlefish court in the shallows, and the walls carry cowries, nudibranchs, and frogfish for the patient. Sharks are scarcer than the wilderness setting suggests, an honest legacy of regional fishing. When the mantas are in, few sites in Southeast Asia match it.

您此行的高光时刻: Oceanic mantas at close quarters, marbled rays stacked in the ledges, open-ocean solitude

地形地貌: Guano-stained outcrop dropping in walls and boulder slopes past 40 m

水流: Open-ocean exchanges wrap the rock; each dive works the lee and the up-current corner.

入水方式: A lone rock in open sea reached only on longer northern itineraries; boats typically stay for several dives.

危险因素: Open-sea current and swell, deep walls, and a long way from help; conservative profiles are part of the briefing.

保育: Manta encounters here depend on undisturbed cleaning behavior; low, still, and reef-side is the rule.

高氧（Nitrox）: 在此值得使用——各潜点深度落在富氧空气（nitrox）能有效延长免减压时间的区间（前提是持有相应认证）。