On the morning of December 8, 1941, about 2000 Commonwealth soldiers, including some 500 New Zealanders, boarded the Sebastiano Venier in Benghazi harbour to be transported across the Mediterranean to Italian POW camps. The men were loaded into the four cargo holds and the hatches were battened down before the Sebastiano Venier  left port with an escorting torpedo boat that had on board officers captured the previous month, including Brigadier James Hargest, who had been captured on November 28.

The Sebastiano Venier sailed across the Mediterranean towards Greece and into the path of the Royal Navy's submarine HMS Porpoise, under the command of Lieutenant Commander Pizey. HMS Porpoise made contact with the ship on December 9, 5km off Methoni Point, off the western coast of the Greek Peloponnese.

At 2.35pm, HMS Porpoise fired the first of four torpedoes, of which the third struck the Sebastiano Venier between the first and second holds below the waterline. The resulting explosion caused the first of some 500 deaths, including 45 New Zealanders, before the Sebastiano Venier was beached as dusk was falling. 

Prior to the torpedo hitting the Sebastiano Venier, lookouts on board had spotted the periscope of HMS Porpoise, reportedly two minutes before the third torpedo struck. This caused panic among the mainly Italian crew, with the captain and most of his crew taking to the lifeboats, leaving the ship to be managed by a German engineer. 

The Sebastiano Venier was taking on water, listing and, because the Italian crew had stopped the engines, had no forward power. Under the command of the German engineer the engines were restarted but the ship was now sinking at the bow, pulling the propeller partly out of the water; with an ever-increasing swell, the ship was finally beached on the rocky shore parallel to the sea walls of Methoni Castle. 

The ship was about 50m from the rocky shore and the consequent evacuation resulted in more deaths, as men were smashed against the rocks. Those who made it ashore were held in a warehouse in Methoni overnight. 

For many of the New Zealanders, this was their second time in Greece as they had been part of the ill-fated Greek campaign. 

Some of the New Zealand POWs from the Sebastiano Venier ended up in PG 78/1, a POW camp holding 220 men, of whom 147 returned to Allied lines after Italy capitulated on September 8, 1943. Eighty-one were among the first batch of 145 former POWs to return to New Zealand in January 1944. [Various sources]