Somewhere out there on the sea floor of Hawke's Bay is a 7m, 2-ton German torpedo.
It has been resting there since January 16, 1945, and for all intents and purposes it would likely still be listed as "live".
For it failed to reach the target it had been directed at — the 720-ton coastal trader Pukeko which had just left the Port of Napier.
For the skipper of the German submarine U862, Commander Heinrich Timm, it was a further disappointment in their quest to knock out allied shipping along the eastern seaboard.
The Port of Napier had been an important part of the supply line to the US forces in the Pacific with "feeder ships" making 34 visits to Napier on the supply runs between 1943 and 1944.
So for Timm and his crew, so far from their homeland at a time when World War II was turning heavily against Germany, the opportunity to sink allied shipping had to be taken, even if their presence in this part of the world had not been clearly planned.
As the late Gerald Shone, author of U-boat in New Zealand Waters pointed out, U862 had effectively fled to the more less-patrolled waters off New Zealand to avoid being hunted and sunk off Australia.
His research showed U-boat Command in Berlin had sent U862 and two other U-boats, which had been part of a 10-strong fleet of submarines stationed in the Far East, on a mission to sink merchant shipping off the Australian coast.
The mission did not go smoothly with two of the submarines being intercepted by allied submarines which had been lying in wait outside the Japanese-controlled Far Eastern bases — but U862 slipped through and on Christmas Day, 1944, it sank the American liberty ship Robert Walker just southeast of Sydney.
Shone wrote that the ensuing hunt for U862 by the Royal Australian Navy and Air Force was "so tenacious and resolute" that Timm made the decision to get well away — and he steered a course toward New Zealand.
The submarine reached the northern tip of New Zealand on January 9, 1945, and got a great navigational fix from the Te Reinga lighthouse which was giving out a light sweep every 13 seconds.
After a couple of fruitless days looking for shipping off Auckland Timm headed down the East Coast and made the risky decision to actually enter Gisborne Harbour on January 15 looking for something to send a torpedo into.
There was nothing, so they headed further south toward Napier and Timm stationed U862 in a stationary position outside the harbour between 11pm and midnight to avoid detection.
They watched the harbour closely, and using binoculars Timm and senior officers were able to see skaters using the Marine Parade rink by the Sound Shell.
First Watch Officer Gunther Reiffenstuhl wrote in his diary entry for January 16, 1945, "We can see the beach cafe with bright red lights, the music plays old songs, several couples are dancing.
"The town on a hill glitters in a thousand lights."
They then saw what was noted as a "little ship" leaving the port and they pursued it.
In the process they came close to another ship "which doesn't see us as nobody is expecting us here".
Just before dawn they dived to attack.
"Commander missed his target," Reiffenstuhl wrote, adding that someone on the bridge of the Pukeko may have spotted the brief wake from the periscope and quickly turned.
The ship also sent a morse code message to the signal station on Portland Island.
"Now we have been noticed here and have to leave," Reiffenstuhl recorded.
Which meant no shore time, although stories went about for a time that some German crew had rowed ashore to milk some cows for fresh milk at Awatoto.
Reiffenstuhl, and other members of the crew in later years after returning to Germany, were bemused, but shot the story down.
"It's nonsense — I don't know who found the idea — it never happened — it was too dangerous."
But it made for a good story.
What did happen was the crew, taking turns for a spot atop the conning tower, were able to watch the joyous sights of people skating and dancing, and hearing music and even laughter.
And firing one single torpedo which is still out there ... somewhere.