The sea is a difficult environment to deal with in an emergency situation.
Submarine rescue requires multinational cooperation and training among NATO Allies and other nations to develop tactics and test cutting-edge technologies and equipment.
The International Submarine Escape and Rescue Liaison Office (ISMERLO) was established by NATO, following the disaster in 2000 with the Russian submarine Kursk, when all 118 submariners on board tragically died.
ISMERLO aims to prevent submarine accidents and respond on a global basis if they do occur.
The NATO Submarine Rescue System (NSRS) is a cooperative project between three NATO countries: France, Norway and the United Kingdom.
It is designed to rescue personnel from submarines in distress and can dive to depths of up to 600 metres.
It consists of three main parts: an intervention system, a rescue vehicle and a transfer under pressure system.
It is the largest fly-away submarine rescue system and can dive up to six hours, four times a day.
On each dive, it can rescue approximately 12 submariners, who will receive medical treatment in its facilities, if needed.
The NATO Submarine Rescue System is available to anyone on request and can be deployed almost anywhere in the world within 72 hours.