Diving enthusiast Alex Mustard, 36, has made several discoveries while exploring 40 feet beneath the water surface. His pictures, taken while investigating the inside of eerie ship wrecks, include barnacle-covered motorbikes, once meant for British troops fighting during World War II. (Photo: VCG)

A sunken World War II ship has been hauled out of an Australian harbor after several failed attempts.

The boat, known as HDML 1321 during the war, was used by Australia's Z Special Unit during the war to transport commandos behind enemy lines in Papua New Guinea (PNG) for covert operations.

A small group of volunteers operating under the name Save Motor Launch 1321 have been trying to recover the ship for almost two years after a previous group failed in its attempts.

Robert Welfare, chairman of the group and a full-time lawyer, said he shed a tear when the boat floated to the surface on Sunday.

"We did it," Welfare told the Australian Broadcasting Corporation (ABC) on Monday. "Lots of pumps, lots of volunteers, lots of time, lots of planning."

The group used a 120,000-Australian dollar ($89,138) purpose-built submerged trailer, paid for by the Northern Territory (NT) government, with a system of several water pumps to make the boat float again.

A crane was used to pull the boat from the water once it was floating.

"It was just wonderful that we got it right on the third attempt," Welfare said. "It shows what can be done if everyone pulls together, pulls on the same oar."

Welfare's group plans to restore the boat until it is fit to return to sea.

"It's a very historic object," he said. "Many people lost their lives on this boat, it saved people off beaches, it took Americans off beaches, it took Australians off beaches."

"It contributed significantly to the (WWII) effort on the islands north of us here."