What is an MMSI and Why you need an MMSI?

What is an MMSI?

An MMSI is a unique nine digit number that is entered into certain marine radio communications equipment. When using this equipment to send a distress alert, or to indicate some other emergency, the number assists emergency services to identify you and/or your vessel.

Since marine VHF transceivers now operate under a class licence, there is no requirement for an official call sign and maritime ship station licence, but the operator must have a minimum radio operator qualification of a AWQ or Short range certificate of proficiency (Marine radio operator’s VHF certificate of proficiency). However, for MF/HF transceivers, Long range certificate (Marine radio operators certificate of proficiency) is the minimum qualification.

Why you need an MMSI?

You are required to apply for an MMSI if you have the following equipment:

fixed very high frequency (VHF) radio with digital selective calling (DSC)

a handheld VHF DSC

high frequency (HF) DSC

automatic identification system (AIS)

Similar to a text message, DSC can be used to establish initial contact between vessels and stations. You are identified by your MMSI number and able to indicate the priority of your message, for instance whether it is a distress, emergency, security or routine message.

If your equipment is connected to a GPS receiver, the message will also provide the vessel’s position and time at which the position was valid.

DSC equipment is a part of the global maritime distress and safety system (GMDSS).

AIS is an automatic system used on ships and by vessel traffic services for identifying and locating vessels (class A or class B transceiver) and for safety of navigation.

All large commercial vessels subject to the Safety of Life at Sea Convention (SOLAS) must carry DSC and AIS equipment appropriate to their area of operations. However, small recreational and fishing vessels may not require DSC equipment unless they plan to operate offshore or proceed overseas.

Coast stations may also be equipped with DSC, and in this case, also require an MMSI.