USAT Liberty Wreck

The Liberty may be the most accessible great wreck in the world: a US Army transport torpedoed in 1942, beached at Tulamben, then nudged back into the sea by the 1963 Mount Agung eruption. Sixty years of coral growth have turned the broken hull into a reef in the shape of a ship, its ribs and swim-throughs upholstered in gorgonians and black coral trees. At first light a resident school of bumphead parrotfish files out of the wreck like commuters, and dusk brings hunting trevally and flashlightfish deeper in the structure. Garden eels stipple the sand, pygmy seahorses hold on the fans, and barracuda hang off the stern. Depth options from five to thirty meters suit nearly everyone, which explains both its fame and its morning crowds.

The moment you come for: Dawn bumphead parade; coral-encrusted swim-throughs; shore access with big-wreck atmosphere.

Topography: Black volcanic sand slope with the broken 120-meter hull lying parallel to shore.

Current: Usually calm; occasional longshore current and surge in the shallows.

Entry: Walk-in over rounded black pebbles a short swim from the wreck; porters famously carry tanks to the water. Entries get sporty when swell runs.

Hazards: Surge over the entry pebbles, silt inside confined sections, and crowds; penetration beyond open swim-throughs needs training.

Conservation: Heavy traffic is the site's main pressure; avoid touching the structure, and dive early or late to spread the load.

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