HM Coastguard coordinates all maritime search and rescue (SAR) operations in the UK through a network of coastguard stations, operating 24 hours a day. Staff in operations rooms coordinate the response to a variety of incidents from lost or missing people to climbers stuck on cliffs or vessels missing at sea.

HM Coastguard receives requests for assistance in many forms including 999 calls, mayday and pan pan broadcast, calls on VHF DSC and Channel 16 and satellite distress calls.