The MV Pavit spent three days without any power and her crew were suffering badly from sea sickness, the ship was being battered by storms, and the pumps were struggling to keep the water at bay.
Her master flashed an SOS which was passed on to Type 23 frigate HMS St Albans via Falmouth Coastguard, asking for his ill sailors to be lifted off.
Hearing the distress call, HMS St Albans broke off from a maritime security sweep of the Arabian Sea to aid the stricken sailors:
"This was a desperate situation for the crewmen on board, who had been without engines for three days in severe weather conditions, and reported that several crew members had fallen seriously ill," said Falmouth Coastguard watch manager, Alan Loveday.
The Saint, as HMS St Albans is affectionately known, scrambled her 829 Naval Air Squadron Merlin helicopter with the ship's medical officer on board to offer assistance to the 21-year-old tanker's crew.
When the helicopter arrived on the scene, the merchantman's master decided all souls aboard should be rescued as the 2,000-tonnne vessel looked in imminent danger of foundering.
It fell to aircrewman Petty Officer 'H' Henson from Whitehaven to go down on the wire and pick up the 13 sailors as the Pavit moved violently in the bad weather:
"We're glad that we could help the ship's crew. They were relieved to see us and it was good to be able to get them all off safely," he said.
"The conditions were demanding; the stricken vessel was pitching and rolling in heavy seas. It's times like these when your training kicks in and you have confidence in the kit, the helicopter and the aircrew."
The ill crewmen were treated and all the Pavit's personnel were transferred to their sister ship MV Jag Pushpa nearby which was coming to their aid.
St Albans' Commanding Officer, Commander Tom Sharpe said:
"As fellow mariners, if we are in a position to render assistance to a stricken vessel requesting our help, then we will do.
"The monsoon-induced sea state had not been kind to the MV Pavit and with no power and taking on water, her master and the crew were grateful for our quick response and assistance.
"St Albans is out here as a presence to deter acts of smuggling or piracy, but this tasking is just as important and can occur at any time."
HMS St Albans has now resumed her patrol of the region while efforts are ongoing to salvage the Panama-flagged Pavit.