Letters – by our Readers


Hi Pat,

Gary at Twin Rivers suggested you might be able to guide me to a solution to an issue that has come up. It appears to me that another boat by the same name as mine, Dream Weaver, has pirated my MMSI. It is probably inadvertent, but still not right.

This was discovered by a friend that monitors my travels on vesselfinder.com. What he saw was that as I shut down my boat AIS, it would jump to this other boat that is located at Dana Point. I contacted the FCC, and they said there was nothing that they could do. I contacted the Coast Guard and they could do nothing, but did think that in an emergency that they would figure it out. I spoke with my local Coast Guard Aux that does my annual inspections and he had no answer. I have also made several calls to the Dana Point Marina to speak with the Harbor Master. I also sent him a letter requesting his help and followed up with a phone call. No return calls. No love there.

So I called Gary at Twin Rivers because I’ve known him since I purchased my boat in 2012. He suggested that you might be a source for where I can go next. My ship station is through the FCC, and it is tied to my EPIRB as well as my boat’s DSC. I would rather not go through the bother of getting my unit’s MMSI changed.

I do not know if this gives you any ideas for your column in Bay & Delta Yachtsman. And maybe I am making a bigger deal out of this than necessary. I am planning to go up into Canada this year when the border opens up, and would rather not have this become an issue. I now reside in Bremerton, WA even though I keep my Sacramento number. Hope you can help.

John Parvis


Unfortunately, this is a problem that you share with many other boat owners, and yes your letter has sparked an article on the DSC system. Please see Lessons Learned in this issue.

As the DSC system was designed, the MMSI was to belong to the ship and stay with her through different owners, similar to the vessel documentation number. To help enforce this policy the equipment manufacturers designed into their AIS transmitters and VHF radios the ability for the user to program the MMSI once and in a few cases twice. After that, the radio must be deinstalled and sent back to the factory for a memory wipe and reprogramming. So even if you obtained a new MMSI you may not be able to program your existing equipment yourself with it. NOAA does not care, you can change your EPIRB registration pretty much anytime on their website at httpsccwwwddsarsatddnoaaddgov/beacond dhtml.

Here is a scenario that I have seen several times:

Boater A sells his boat, Dreamweaver, to boater B and fails to contact the FCC to deauthorize the MMSI. Boater B fails to contact boater A as part of the transaction to release the MMSI.

Boater A buys a new boat, Dreamweaver II, and promptly upgrades the navigation system including the VHF radios and AIS transceiver. Installer asks for his MMSI in order to finish the install and test his new AIS transmitter. Guess what number boater A gives the installer? Now more than one boat shares the same MMSI.

Not sure I like the USCG answer that in an emergency they will figure it out. They may, but how long a delay? In an emergency minutes count.

When the Coast Guard receives a DSC emergency call or an EPIRB activation, one of the first things they do is call the emergency contact number that was provided during MMSI registration. The vast majority of EPIRB activations are accidental, and the authorities do not have the resources to immediately launch a SAR without first confirming that it really is an emergency and not some guy in his garage trying to change the EPIRB battery himself and then inadvertently activating it.

So back to your problem.

You have done more than anyone I know to resolve the conflict. I do not have any suggestions other than trying to work with the controlling authority here, the FCC. Even if they do take action, it will start with a letter to boater A demanding he stop transmitting an unassigned MMSI. I do not know, but I can see this taking many months if not more, but in the end you will most likely be successful.

It may be easier to bite the bullet and spend the $100 for a new MMSI from the FCC and hope that your equipment will allow field reprogramming.

Keep in mind that there is nothing to stop boater C from pulling a 9-digit number out of thin air and programming his system. Or perhaps he gets a real number, makes a mistake when entering it and when he finds out that he must send the equipment to the factory for a memory wipe he decides that he likes the new number just fine. Besides, we are just wasting money on emergency equipment that we will never need! Right?

Please let me know how you finally resolve this issue so that we can share the information with other readers of the Bay & Delta Yachtsman Magazine.

Best, Pat H

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