The UK Royal Navy's third of the seven Trafalgar-class submarines, HMS Tireless, has arrived in the southern Indian Ocean to support the search for Malaysia Airlines flight MH370.
The submarine will use its advanced underwater search capability to contribute to the attempts to locate the plane, which disappeared on 8 March.
Meanwhile, the Royal Navy Hydrographic Oceanographic (SVHO) multi-role Survey vessel, HMS Echo, will assist in the search for the transponder on the black box.
In addition, HMS Echo will look for debris on the sea's surface using its environmental assessment capability while optimising search operations.
Technical assistance and specialist capabilities from across the Ministry of Defence, the Hydrographic Office, Department for Transport and the Met Office are being provided by the UK Government.
The maritime operation also involves four Royal Air Force personnel on secondment to the Royal Australian Air Force and Royal New Zealand Air Force.
An Australian Navy warship, Ocean Shield, equipped with a US-manufactured Towed Pinger Locator (TPL-25) and a Bluefin-21 autonomous underwater vehicle (AUV) has been dispatched, as the multi-national search for MH370 reaches its fourth week.
The Beijing-bound aircraft vanished off radar screens an hour after its takeoff from Kuala Lumpur on 8 March, and is assumed to have crashed in the southern part of the Indian Ocean with no expected survivors.
Image: HMS Tireless with its crew. Photo: courtesy of Royal Navy.