RYA SRC MMSI Numbers 1 — Questions and Answers
Question 1: What does MMSI stand for?
- Maritime Mobile Service Identity (Correct answer)
- Marine Mobile Station Identifier
- Maritime Monitoring Safety Instrument
- Marine Message Service Index
Correct answer: Maritime Mobile Service Identity
MMSI stands for Maritime Mobile Service Identity. It is a unique nine-digit number assigned to a vessel's DSC radio, functioning as a maritime telephone number for digital communications.
Question 2: How many digits does an MMSI number contain?
- Nine digits (Correct answer)
- Six digits
- Twelve digits
- Seven digits
Correct answer: Nine digits
An MMSI number always contains exactly nine digits. This standardised length ensures consistent identification across all DSC radio equipment and coast station databases worldwide.
Question 3: What do the first three digits (MID) of a vessel MMSI indicate?
- The country of registration (Correct answer)
- The vessel's gross tonnage category
- The vessel's port of registry
- The year the MMSI was issued
Correct answer: The country of registration
The first three digits of a vessel MMSI are the Maritime Identification Digits (MID), which identify the country where the vessel is registered. The UK MID is 232 to 235.
Question 4: What is the UK Maritime Identification Digit (MID) range?
- 232 to 235 (Correct answer)
- 200 to 205
- 250 to 259
- 220 to 229
Correct answer: 232 to 235
The UK's Maritime Identification Digits range from 232 to 235. A UK-registered vessel's MMSI will begin with one of these three-digit codes, identifying it as a British vessel.
Question 5: Who should a recreational boat owner in the UK contact to obtain an MMSI?
- Ofcom (Correct answer)
- RYA
- MCA
- Trinity House
Correct answer: Ofcom
UK recreational boat owners must apply to Ofcom for their vessel's MMSI. Ofcom issues the MMSI as part of the Ship Radio Licence, which is required for any vessel carrying a VHF marine radio.
Question 6: Can an MMSI be transferred to a new owner when a vessel is sold?
- No, a new MMSI must be registered by the new owner (Correct answer)
- Yes, MMSI numbers stay with the vessel permanently
- Yes, with Ofcom approval and a fee
- No, the MMSI is cancelled and never reused
Correct answer: No, a new MMSI must be registered by the new owner
MMSIs are registered to the owner, not the vessel. When a vessel is sold, the new owner must register a new MMSI with Ofcom. The old MMSI should be cancelled to prevent false distress alerts.
RYA SRC MMSI Numbers 1
What does MMSI stand for?