The LVT-4A is one of the most unusual dive sites on the NSW coast: an amphibious tank sitting upright on the seabed off Stockton Beach. Grey Nurse Charters records that it was an ex-US Army vehicle used in the Pacific from 1944 and nicknamed the Water Buffalo, armed with a 75 mm howitzer and a .50 calibre machine gun. In 1954, during an Australian Army exercise, a squall hit the column of amphibious vehicles at 4 am; 12 of the 19 vehicles sank, and three men drowned.

The vehicle that divers visit lies about halfway up Stockton Beach in 33 m. It sits upright, and Grey Nurse Charters notes that live ammunition can still be seen in the turret - a sobering reminder that this is a war-era relic, and that nothing should be touched. The hull, tracks and turret form a compact structure on open sand, so the dive concentrates on this single object.

Marine life has colonised it as it would any isolated structure: Grey Nurse Charters lists small reef fish, morays and hermit crabs, and encrusting sponges and ascidians cover the armour. The contrast between the military form and the soft growth makes it popular with photographers. The long ride from Newcastle Harbour is the main barrier, along with the depth.

At 33 m the dive suits Deep-certified divers with experience, and nitrox helps. Because other vehicles from the 1954 exercise also sank, the area has further research potential for experienced wreck divers. For most divers, it is a rare chance to see a WWII armoured vehicle underwater in Australia.

Charters and private boats leave from Newcastle Harbour - the Carrington or Stockton boat ramps, or Newcastle Cruising Yacht Club/Marina precinct on Wharf Road - and run out past Nobbys Head through the harbour entrance, a busy commercial shipping channel where port traffic has right of way and Port Authority rules apply. Parking with trailer bays is available at both ramps. The tank lies about halfway up Stockton Beach in Stockton Bight - a long ride of 30-40 minutes from Newcastle Harbour.

Boats from Port Stephens (Nelson Bay) can also reach it. No public mark is published.

The Newcastle offshore sites are exposed to the full Tasman swell and generally need less than about 1.5 m of swell and light winds; strong southerlies and north-easterlies both make the run from the harbour uncomfortable. Visibility is the main variable: the Hunter River outflow through the harbour entrance stains the water for days after rain, so the best diving follows a dry spell and is usually timed around high tide, when clean ocean water pushes in. The East Australian Current brings warmer, clearer water from late summer into autumn, while winter can be cold (around 15-16 °C) but surprisingly clear.

Stockton Bight is fully exposed to southerly and easterly swell and the long ride means a stable forecast for the whole day is needed.

Descend the shot to the tank. Circle the vehicle slowly, viewing the turret and tracks, and check the sand for other debris. Do not touch or disturb the ammunition.

Return to the shot and ascend with a safety stop.

Nitrox recommended. Unexploded ordnance - do not disturb; report to authorities if moved.

Grey Nurse Charters dives the Newcastle wrecks and reefs by arrangement from Newcastle Harbour and Swansea; Dive Newcastle and local clubs dive them from private boats. There is no fixed daily schedule - trips run on demand and conditions.