HMS Argyll has hunted down submarines in the Philippine Sea during exercises with allied navies from Japan and the United States.
This was the first time these navies have combined like this as they tested their specialist anti-submarine warfare skills.
Japan’s helicopter destroyer JS Izumo worked with the Plymouth-based frigate to hunt down a US Navy Submarine, which was playing the part of the enemy during two days of training.
Argyll has already worked alongside the Japanese navy (Japan Maritime Self-Defence Force) during her current deployment – a nine-month mission to the Gulf and Pacific – but this is the first time the three nations have worked together in this region.
"Sharing the Royal Navy’s expertise and experience with our partners and allies right across the world emphasizes the UK’s commitment to promoting international security and stability," said Commander Toby Shaughnessy, Commanding Officer of HMS Argyll.
As part of the exercises, Izumo and Argyll both deployed helicopters to hunt the submarine.
The Type 23's Wildcat was loaded with a Test Variant Torpedo (TVT) by 208 Flight before launching off Argyll's deck to step up the search for the US submarine.
The Japanese also sent up their anti-submarine Seahawk helicopters alongside a Maritime Patrol Aircraft.
"Given the increase in maritime traffic worldwide and current events, the importance of increased collaboration and cooperation between our three highly capable and like-minded services can't be overstated,” said Captain Katsuyoshi Motoyama, Commander of Izumo.
"We all share a common vision of enhancing the operational effectiveness of our maritime forces."
Argyll is currently on a nine-month deployment and following these exercises came alongside at US Naval Base in Yokosuka, Japan.
After operations during the Christmas period, this was a chance for the ship’s company to explore capital Tokyo and head into the surrounding mountains above Yokosuka to take part in winter sports.