The international distress, safety, and calling frequency at 156.8 MHz; all SOLAS ships must maintain a continuous watch on this channel.
Quick facts
Regulation
SOLAS Chapter IV
Frequency
156.8 MHz
Channel
VHF Channel 16
In practice
Bridge watchkeeping officers must monitor Channel 16 at all times when at sea, in accordance with SOLAS V/33 and the regulations of vessel traffic services in coastal waters. The introduction of GMDSS digital selective calling on Channel 70 did not eliminate the mandatory watch on Channel 16, which remains the only frequency reliably monitored by all classes of vessel from yachts to VLCCs. Officers must be familiar with correct distress, urgency, and safety call procedures and must know how to transmit a MAYDAY relay on behalf of a vessel in distress that may not be capable of transmitting on its own account.
Regulatory detail & full definition
VHF Channel 16, operating on 156.8 MHz, is the international distress, safety, and calling frequency designated by the ITU Radio Regulations and SOLAS Chapter IV as the channel on which all SOLAS vessels and coast radio stations must maintain a continuous listening watch. Its allocation as the universal hailing channel means that any vessel wishing to establish communications with another must first call on Channel 16 and then agree to switch to a working channel for the actual conversation, keeping Channel 16 free for distress traffic. All Mayday, Pan-Pan, and Securité calls are transmitted on Channel 16 and may be addressed to all stations or to a named coast guard.
Bridge watchkeeping officers must monitor Channel 16 at all times when at sea, in accordance with SOLAS V/33 and the regulations of vessel traffic services in coastal waters. The introduction of GMDSS digital selective calling on Channel 70 did not eliminate the mandatory watch on Channel 16, which remains the only frequency reliably monitored by all classes of vessel from yachts to VLCCs. Officers must be familiar with correct distress, urgency, and safety call procedures and must know how to transmit a MAYDAY relay on behalf of a vessel in distress that may not be capable of transmitting on its own account.