When is a Sécurité message transmitted on VHF and on which channel?

A. To request a radio check from another vessel

B. To broadcast a navigational or meteorological warning — e.g. a floating container, unlit vessel, or debris reported — transmitted on Ch 16 (or as directed by Coastguard, typically Ch 67 in UK)

C. To report a vessel in distress on behalf of the casualty

D. To cancel a Mayday call when the vessel is safe

A. To send a digitally coded distress alert containing the vessel's MMSI and position automatically to all DSC-equipped stations and the Coastguard

B. To broadcast weather forecasts to other vessels

C. To make telephone calls from the vessel to shore

D. To operate the radar system remotely

A. A GPS waypoint identifier used in coastal navigation

B. Maritime Mobile Service Identity — a unique 9-digit number identifying the vessel; without it a DSC distress alert cannot identify the vessel to rescuers

C. A VHF channel number allocated by Ofcom for distress use only

D. A vessel survey certificate number required by the MCA