What are those four letters (or numbers and letters) after a ship's name?

Question

In radio communication, it's normal to use the ship's name and four letters (or letters and numbers) after it's name.

For instance, "This is Black Pearl - PWST"

Can anyone tell me what's that?

Is that the call sign or the MMSI number?

Thanks

Answer 1

Call sign.  An MMSI is a long string of numbers and letters

Answer 2

That is the vessel's radio station call sign. You can tell it's nationality from the first letter.

Answer 3

Yes...

    "MMSI" stand for "Marine Mobile Service Identity"

Whats it for?

     By using a VHF radio with Digital Select Calling (DSC) capability, with on board GPS, you can increase your safety and dramatically decrease the time it may otherwise take to be rescued. With a single push of a button, your radio will send your MMSI number (and thus your and your vessels identy and GPS location over the radio for emergency rescue purposes.

The benefit of this of course, is that it takes the "search" out of search & rescue... they will instantly know who and where you are...

     Authorized by both the Federal Communications Commission and the U.S. Coast Guard - MMSI numbers assigned to vessels with DSC capable radios THAT ARE NOT REQUIRED by law to carry a radio, and DO NOT MAKE international voyages or communications.

This is a free service for recreational vessels only - that otherwise are NOT required to have an FCC ship station license.  

Vessels required to carry a radio on board are "compulsory equipped" vessels must and go directly through the FCC to obtain an MMSI.

If you have a radio, on your recreational vessel and want to get a MMSI number, you can do it FREE on line at the following link:

http://www.boatus.com/mmsi/

Merchant vessels are assigned call signs by their national licensing authorities. In the case of "PWST" states such as Panama, register vessels which under "flags of convenience" for ship registration, call signs for larger vessels consist of the registry, national prefix plus, two or three letters (for example, "PWST", the first two letters tell us it is a US vessel registered in Panama.  United States civilian vessels registered in the US are given call signs beginning with the letters  "W" or "K". Originally both ships and broadcast stations were given call signs in this series consisting of three or four letters, but gradually American-flagged vessels were given call signs with mixed letters and numbers.

Recreational vessels with VHF radios may not be assigned call signs. In which case, just the name of the vessel is used instead.

Happy & Safe Boating!

Capt. John