Broken Rock

The boat drops divers a short way off the reef, and they make their way to it, often aided by current. Many guides take the base first: at about 25m, in slack water, you can swim a full circle around the rock before the route turns to the canyon. The split runs diagonally down the middle of the thila, and most guides lead the group straight through it.

Inside, the walls carry soft corals, gorgonian fans and sponges, continuing into the smaller cracks and crevices off the main gully. One diver whose guide named Broken Rock as his favourite site remembered a gap swim-through festooned with pale pink sea fans and masses of fish. East of the thila a second rock plateaus around 17m, where schools of bluestripe snapper and barracuda gather. Humphead wrasse, turtles and moray eels are among the animals divers can expect along the way.

A diagonal fault runs across the whole thila, and the dive is built around it. The canyon gives the site its name: a gully you swim through, hung with fan corals that stand out from the walls and thick with soft coral. The geometry also sets the shape of the day. The structure offers a base circuit, a canyon pass and a separate plateau, so one dive covers three different habitats around a single pinnacle.

In the gully, good buoyancy control and distance from the corals matter more than anything else; the walls are lined with sessile life that a fin or a hand will damage. The current in this channel can be strong, so time the canyon and the base with the guide.

The reef top sits at about 12m, which leaves no shallows for the safety stop. Without a line you hang in open water and can drift off the site, so the surface marker buoy goes up with you on every ascent.