IMO number & Maritime Mobile Service Identity ( MMSI)
Every propelled, sea going merchant vessel of 100 GT and above has an unique 7 digit identification number starting with “ IMO” marked on its hull ( at stern) . This number is never reassigned to another vessel and is to be marked on every certificate issued for the vessel in question.
Vessels exempted from having an IMO number are pleasure yachts, vessels without mechanical means of propulsion, wooden ships, war ships, troop ships, vessels solely engaged in fishing, floating docks etc.
The MMSI, Maritime Mobile Service Identity, number is assigned to all vessels by IHS Fairplay, formerly known as Lloyd’ s Register – Fairplay. It is especially important for emergency communication via using DSC( Digital Selective Calling) feature of the radios on board and also in emergency situations, in case of sinking for instance, where the EPIRB( Emergency Position Indicating Radio Beacon) is activated automatically and send the information to the related authorities about the disaster.