The Meigs was the biggest ship in Darwin Harbour on 19 February 1942 and remains the largest and most rewarding of the raid wrecks. Built in 1921 by the Los Angeles Shipbuilding and Dry Dock Company at San Pedro, California, she was a 131 m, 12,568-ton US Army transport with a straight stem, counter stern, two decks and three masts. She had come to Darwin with a convoy carrying troops and supplies intended for the relief of Portuguese Timor.

During the raid she was hit by numerous bombs, machine-gunned and finally struck by aerial torpedoes; remarkably only one or two of her 66 crew were killed. After the raid her masts could still be seen above the water. 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. Fujita cut the Meigs off at the waterline around 1960 but was not allowed to take the American-owned cargo, and that is what makes the dive. The wreck lies roughly north-south in about 18 m and is a vast jumble of steel on a silty bottom.

A Bren gun carrier is recognisable in the bow, military trucks lie mostly buried in the holds, lengths of railway iron cross the midships section and piles of rifle ammunition lie in dumps. Gorgonian fans and sponges cover parts of the structure. Local divers reckon it takes about three dives to see it properly, and it rewards repeat visits as the sand shifts and exposes different cargo.

Its moderate depth makes it the best introduction to Darwin's WWII wreck diving for divers who can cope with low visibility, and Darwin Dive Centre notes that Open Water certification is adequate for most of the harbour wrecks when conditions are good.

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.

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 neap slack and orient to the north-south line of the wreck. Plan several dives to cover it: one on the bow to find the Bren gun carrier, one along the midships railway iron, one on the stern section. Hold 15-18 m, move slowly to avoid silting, turn at half gas and return to the shot for the ascent and safety stop.

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.