RYA SRC MMSI Numbers 2

Question 1

What is the MMSI format for a life-saving appliance (e.g., EPIRB or life raft)?

Accepted Answer

97XXXXXXXX (10 digits starting with 97)

Answer

MMSIs for life-saving appliances such as EPIRBs and SARTs use a 10-digit format beginning with 97, distinguishing them from vessel MMSIs (9 digits) and coast station MMSIs.

Question 2

What does a group MMSI allow?

Accepted Answer

A fleet manager to call multiple vessels simultaneously

Answer

A group MMSI allows fleet operators to make a single DSC call that is received by all vessels sharing that group MMSI, enabling simultaneous contact with an entire fleet rather than individual calls.

Question 3

What is the all-ships MMSI used for DSC all-ships calls?

Accepted Answer

999999999

Answer

The all-ships MMSI is 999999999 (nine nines). Using this MMSI in a DSC call transmits to all vessels within range, similar to an all-ships broadcast on Channel 16.

Question 4

Should an MMSI be programmed into a VHF radio before or after purchase?

Accepted Answer

Before use — it must be programmed before the radio is operated

Answer

The MMSI must be programmed into the DSC radio before the radio is used. Operating a DSC radio without a programmed MMSI means it cannot function correctly for distress alerting or DSC calls.

Question 5

What happens if two vessels share the same MMSI?

Accepted Answer

DSC calls and distress alerts become unreliable and coast stations cannot identify the correct vessel

Answer

If two vessels share an MMSI, any DSC distress alert will identify the wrong vessel to rescuers, creating potentially fatal confusion. Coast station databases will show incorrect vessel details, seriously compromising SAR effectiveness.

RYA SRC Practice Test

RYA SRC Practice Test

RYA SRC MMSI Numbers 2