Batu Bolong

Batu Bolong, the hollowed rock in the middle of the Lintah Strait, is a small target with absurd returns. Current splits around the pinnacle, and everything that cannot hold in the flow crowds into the lee: anthias in drifts so thick the wall seems to steam, turtles wedged into crevices, Napoleon wrasse and giant trevally hunting the edge where protected water meets moving water. Divers work up the sheltered face in switchbacks, keeping inside the calm triangle while dogtooth tuna and whitetips patrol just outside it. Coral cover is immaculate because nothing careless survives here, neither anchors nor sloppy divers. Rounding a corner into the stream is the classic mistake; good guides make sure nobody finds out why.

The moment you come for: Wall-to-wall fish in the lee; hunting tuna and trevally at the current line; pristine coral on a mid-strait spire.

Topography: A rock spire in mid-strait, barely breaking the surface, walls plunging steeply on all sides.

Current: Ferocious tide races past both sides; dives work the protected lee in a zigzag, never rounding the corners, and are timed to the tide table.

Hazards: Down-currents and washing-machine water at the corners; stay in the lee, follow the guide's line, and abort rather than fight the tide.

Conservation: No moorings for careless operators and no room for poor buoyancy; the site's condition depends on disciplined guiding.

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