What to do when buying a used boat that already has an MMSI number – I get asked this question a lot, so here is my typical answer. First of all, if you sell a boat that has your MMSI number and your contacts, BE SURE TO CANCEL that number with the organization that provided that number. Otherwise, that may be a big liability as the new owner could possibly make a bogus distress call and any possible search costs could be charged to you. Another advantage of the previous owner (PO) cancelling that number is it should go in the “pool” of available numbers and the new owner could get it assigned to them. You may be lucky and have an older DSC radio that allows a second entry of the User MMSI number. Check out the manual for your radio and see if it allows a second entry. If it doesn’t, try to contact the PO to see if he/she will give you the logon credential (338 numbers in the USA) to Boat US or other providers of MMSI numbers and logon to change contact information. If that doesn’t work, maybe the PO has been kind and he filled out a Boat US “Transfer MMSI” form and you can re-register that MMSI number with your information. They currently have a link to “Transfer Request Form”. If you have a FCC (in the USA) MMSI number, the PO may have cancelled that number. It really should be cancelled anyway, to reduce liability. One other possibility may be that the PO put the logon credentials in the radio’s owner’s manual–you should look there. If none of these work you could hire a boat electronics firm to “reset” the MMSI number, or send the radio back to the manufacturer and have them “reset” the number.

Hot off the press, a new marine DSC radio has been announced from Standard Horizon. The model number is GX6500 and also includes an AIS transponder (transmitter) in addition to receiving AIS information and a fully functional marine VHF DSC radio. Their new technology includes a wireless RAM mic and a large screen. Since it has just been announced, there is not much info about it and it is not available for purchase yet. The best info can be found here.

Even though this is not specifically DSC related, I would like to mention there are a few new things going on in the marine VHF channels. This page shows new channel numbers, like 1001, 2006… You should also notice the actual frequency is different from the original channel 1, 6 and the new 1001 series of channels. This looks like a major change to me, old radios will not be able to communicate on new ones. Also check out this page. There you will see new uses VDSMS. This stands for VHF-FM Digital Small Message Services. My impression is we will be able to send SMS messages over these channels. The best information I have found is on this page. If I get more information, I’ll mention it here.

After March 25, 2011 fixed mount DSC radios added improved features including two channel CH 70 reception (Class D DSC). This same Class D radio became a requirement in portable DSC radios in March 25, 2015. Prior to these Class D radios, the radios in use were known as RTCM SC101 standard. The FCC actually states: Manufacturer, Importation, Sale or Installation of RTCM SC101 Radios are Prohibited On March 25, 2011 (for fixed mount), and March 25, 2015 for portable devices.

There are only 5 working pleasure boat channels: 68, 69, 71, 72 and 78. Channel 6 can be used for Safety conversations, channel 9 can be used as a hailing and radio test channel and channel 16 is dedicated for distress or hailing another vessel–not radio test.

Channel 27 is used in many areas for Sea Tow radio checks. You would make a test call, and if there is a Sea Tow radio close to you, your actual voice would be re-played. Check out their website to see if a station is close to you.

If anyone wants to actually see and record DSC messages, the Windows DSCdecoder program can be used. You would need either a ham or older marine radio that hears the tones on 156.525 MHz, actually marine channel 70. You would get a suitable cable to connect the radio to the microphone input of a PC. If anyone wants more information, click the Contact Us page and send a message.

Over and Out – The most commonly misused procedure words are “Over and Out”. Over means that you expect a reply. Out means you are finished and do not expect a reply. It is contradictory to say “Over and Out”.

Radio checks are prohibited on Channel 16. Channel 9 or Channel 27 automated is the proper place for radio checks.

Prohibited Communications – The FCC prohibits the following communications: False distress or emergency messages; Messages to “any boat” except in emergencies and radio tests; Messages to/from a vessel on land; Obscene, indecent or profane language.

To see who needs a ship station license, see this page. This page also discusses if you need a FCC MMSI number (in the USA). In summary, you need a FCC MMSI number if your vessel is: a cargo vessel over 300 gross tons; certified to carry more than 6 passengers for hire; power driven over 20 meters (65.6′); more than 100 gross tons certified to carry at least one passenger; tow boat more than 7.8 meters (25.6′); un-inspected commercial vessel; required to carry a AIS transceiver; planning to go to foreign ports.

If you are UK registered you are supposed to have a separate MMSI for your portable VHF DSC radio. For more information, click this link.