Distress Communications

For grave and imminent danger when assistance is required, send the VHF DSC distress alert on Channel 70 by pressing and holding the covered control until the set confirms it has sent. The alert identifies the vessel by MMSI and can include position and time when valid navigation data reaches the radio. It carries the selected nature of distress, or an undesignated distress if none was selected.

On receiving a DSC acknowledgement, or after about 15 seconds, transmit the voice MAYDAY call and message on Channel 16 when circumstances permit. Give MAYDAY three times, vessel name three times, call sign or other identity and MMSI, then repeat MAYDAY and state vessel identity, position, nature of distress, assistance required, people on board and other useful information before OVER.

PAN PAN is for an urgent concern about the safety of a person or vessel below the MAYDAY threshold. Current MCA small-boat guidance uses a DSC All Ships Urgency call with a nominated working channel, an announcement on Channel 16 and the full message on that working channel. Escalate to MAYDAY when the developing facts meet the distress threshold.

An EPIRB transmits a 406 MHz satellite distress alert; GNSS-equipped units can include position. A beacon carried on a UK-registered ship or watercraft must be registered with the UK Beacon Registry and kept current. A radar SART is a close-range locating aid. VHF range depends strongly on antenna height, so use complementary alerting and locating methods rather than treating any one device as a rescue guarantee.