[header] How to call mayday from a marine vessel [title] Listen to the radio frequency. [step] If it is clear that the coast guard or other sea rescue agency has not responded after a single repetition and a two-minute wait, you must seek to contact the coast guard or other sea rescue agency on behalf of the distressed vessel. [title] Say : [step] Mayday relay, mayday relay, mayday relay. 
This is the [" your vessel and callsign "]. The following distress call was received from [" distressed vessel's name "].