Lima Rock

Lima Rock is Musandam's headline act: a sheer-sided islet whose cliffs continue underwater as walls and boulder slopes swept by the Strait of Hormuz's tidal engine. The water is rarely clear and never empty - fusiliers and snapper school in mid-water curtains, jacks strafe the edges, and the plankton haze that limits visibility is exactly what draws mobula rays, which pass in squadrons, and the occasional whale shark in the warm months. Honeycomb morays the width of drainpipes hold the boulder gaps, and eagle rays cruise the deeper sand line. Birds wheel off the cliffs through every surface interval. It is a site where divers learn to trade gin-clear water for biomass, and most decide the trade is good.

The moment you come for: Mobula squadrons in season; fish schools dense enough to dim the light; dramatic cliff-to-wall topography.

Topography: Steep boulder-and-wall flanks around a guano-capped limestone islet, shelving to sand

Current: Tidal flow accelerates around both ends; guides choose the lee and time the corners.

Entry: A limestone islet at the mouth of Lima bay, reached by dhow or speedboat from Khasab or Dibba; north and south faces are dived as separate sites.

Hazards: Strong tidal current and eddies at the corners; boat traffic through the strait; variable visibility.

Nitrox: Worth it here — profiles sit in the range where enriched air meaningfully extends no-stop time (with the training to use it).