Text II - Distress Message and Call

The distress call has absolute priority over all other transmissions. All stations that hear it will immediately cease any transmission capable of interfering with distress traffic and will continue to listen on the frequency used for distress call. The distress message will be repeated at intervals by the vessel in distress until an answer is received or until it is no longer feasible to continue. The intervals between repetitions of the distress message will be sufficiently long to allow time for stations, which have received the message, to reply.

Taken from Maritime and IMO SMCP 2001. Rijeka, 2003