[2] For surface running, the boats were powered by two 800-brake-horsepower (597 kW) Vickers two-stroke diesel engines, each driving one propeller shaft.

On seeing the submarine's wash, Pasley's officer of the watch, Midshipman Frank Wallis, RNR, turned the boat hard to starboard and rammed G9 just aft of amidships all but cutting her in two, and she sank less than one minute later with the loss of all but one of her crew, Stoker William Drake.

Meanwhile, Pasley was attempting to locate merchantmen detached from the convoy she was escorting in appalling weather from Russia via Aspö Fjord,[4] 100  km north of Bergen, to Lerwick, and had resorted to displaying a white light halfway up the mast by night for guidance.

Weathering the heavy seas and blinding rain squalls, Cary sighted Pasley's light; forewarned a U-boat was in the area, he gave the order to attack.

The signal was recognised aboard Pasley; her captain, Commander Charles Ramsey, ordered 'Full Astern', but it was too late to prevent his ship ramming the submarine.

Weakened by the effort and numbed by the cold water, Drake was unable to pull himself up on the lifeline lowered, and was only rescued after Able Seaman Henry Old clambered over the side of the destroyer to secure a running bowline around him; he was then hauled aboard and taken below.

Finding Drake laid on his stomach to help rid his lungs of seawater, Ramsey kicked the soles of his feet and demanded to know his nationality.

[7][8] The website 'Wrecksite' gives the final resting place of HMS G9 as approximately 70 miles north west of Bergen in position 61°00′N 3°20′E / 61.000°N 3.333°E / 61.000; 3.333 in 350 m of water.

William Drake remained in the submarine service until the 1930s, and served aboard the frigate HMS Swale as Stoker Petty Officer in World War II; he died in 1974 aged 80.