Japanese midget sub attack commemorated in Sydney

For the first time in 70 years, there were no surviving sailors to commemorate the attack on Sydney Harbour by Japanese midget submarines.

Twenty-one Australian and British sailors died in World War II during the early morning raid on June 1, 1942.

The last two sailors to have survived the attack - Neil Roberts and stoker Ray Major - died in November 2011 and January this year.

But 200 people turned up at Sydney's Garden Island Fleet Base East today to show the dead are not forgotten.

"It's going to be up to us to provide an ongoing narrative for the memory of those that died doing their duty for their country," Commander Shane Moore, director of the Naval Heritage Collection, told reporters.

Hillary Killeen's brother, Kenneth, was 20 when he died in the attack.

"It really hits you in the heart," he said of the memorial.

The most influential people in Sport

"It just shows that other people care as well."

The ceremony also recognised all six Japanese submariners who died.

"Though the Japanese were our enemy then, they too had mothers and fathers and brothers and sisters, just like we did," said Mr Killeen.

"They were human, just like we are."

The first Japanese midget submarine became entangled in the harbour boom net and self-destructed.

The second fired two torpedoes. One of them hit a breakwall and the other sank the wooden ferry Kuttabul, which had been converted to sleeping quarters.

Both missed their intended target, the American cruiser USS Chicago, but the sub escaped the harbour and its wreck was found in 2007.

The commanding officer of the HMAS Kuttabul, Todd Wilson, told attendees the third midget submarine "was hunted through the night and depth charged in the morning twilight".

The crew committed suicide on board.