The USS Peary is the most significant wreck in Darwin Harbour and a war grave. The four-funnel Clemson-class destroyer was built by William Cramp & Sons in Philadelphia and launched in 1919. After the Pearl Harbor attack she fought her way south from the Philippines, was mistakenly attacked by RAAF Hudsons near Sulawesi and reached Darwin on 3 January 1942.

On the morning of 19 February, while getting under way, she was hit by five bombs: the first on the fantail, an incendiary in the galley deckhouse, one that failed to explode, one forward that detonated the magazines and a final incendiary in the after engine room. She sank stern first around 1300, with 88 officers and men lost, including Lieutenant Commander John Bermingham - the heaviest loss of life of any ship that day. Survivor accounts say a gunner was still firing her anti-aircraft gun as she went down.

The 19 February 1942 raids - two waves of Japanese carrier and land-based aircraft, the first and heaviest attack ever made on mainland Australia - sank eight ships in the harbour and killed more than 230 people. In 1959-60 the Japanese firm Fujita Salvage cut most of the wrecks down to or below the waterline for scrap, so what divers find today is usually the lower hull, machinery that was too heavy to lift, and the cargo that the salvors were not permitted to remove. On the Peary that means a broken field of hull plating, frames, boiler and machinery remains and scattered relics lying on a silty bottom in about 27 m.

Live ammunition has been reported among the wreckage. In May 2020 Darwin Sub Aqua Club divers Roland Hugli, Clive Bartsch and Grant Treloar found her two 3 m bronze propellers and shafts more than 2 km from the accepted sinking site, showing that the stern was blown off in the first attack and the ship was effectively disabled from the start; that location is kept confidential. One of her 4-inch deck guns stands in Bicentennial Park on the Esplanade, pointing towards the wreck.

This is a dive for experienced, well-weighted divers comfortable at 30 m in dark, low-visibility water, and it is best treated as an act of remembrance rather than an exploration.

Boat only. Darwin's charter operators leave from Cullen Bay Marina or the Darwin Waterfront precinct and run across the harbour to the site in well under half an hour on a calm neap-tide morning. Private boats can launch at the Cullen Bay public ramp (west of the CBD off Marina Boulevard), the Stokes Hill / Frances Bay ramp beside the Waterfront, or the East Arm ramp for the southern anchorage.

The main wreck lies off the old Stokes Hill / Fort Hill wharf area and within sight of the Bicentennial Park memorial on the Esplanade. Mark the position on GPS before the dive - the wrecks lie in open water with no surface marker - and drop a shot rather than anchoring into protected structure. Parking and trailer bays are at all three ramps; air fills and hire through the Darwin dive shops.

Tide is everything in Darwin Harbour: the spring range is 7-8 m and tidal streams run hard through the harbour, so diving is generally only possible on neap tides (range under about 3-4 m), timed to the slack at high water when clearer ocean water sits over the site. Spring tides bring strong currents and silt-laden water with near-zero visibility. The dry season (May-October) gives the most consistent conditions; the south-east trade winds can chop up exposed water in the afternoon, so mornings are best.

In the wet season (November-April) run-off from the rivers and creeks drops visibility, afternoon storms build quickly, and the harbour is in cyclone season; box jellyfish are present October-May.

Descend the shot at the top of neap-tide high-water slack; the seabed is 27-30 m so bottom time on air is short. Stay low and close to the wreckage, work one direction along the debris of hull plating and machinery, and turn with plenty of gas in hand as the current can pick up quickly after slack. Return to the shot and ascend on it, doing the safety stop on the line with an SMB deployed for the boat cover.

Deep for air in poor light; Nitrox 28-30% extends bottom time slightly. Carry a primary and backup torch; plan conservatively because the current can return abruptly after slack.

Darwin Dive Centre and Dive Darwin run harbour wreck charters only on neap-tide windows (typically a few days either side of each neap, weekends favoured); Darwin Sub Aqua Club dives it on club neap-tide days (members plan dives at Thursday meetings at the Darwin Ski Club). No daily schedule.