I would ask the CG (via land line) if they are aware of the issue. You could also call the radio station and ask to talk to the chief engineer.
Yeah... this occurred to me as soon as I made the post regarding contacting the Harbormaster!
Emailed the station and received the following response:
"Thank you for contacting K*** and reporting our signal on marine channels 22A and 23A.
We’re looking into it. K*** operates two licensed VHF transmitters that carry our programming
and are used to “cue” reporters in the field in cars or aircraft. Of course, they’re not assigned to
Marine radio frequencies, but perhaps one has developed a problem.
In a quick test here at the studio, we can’t hear the interference, but we’re doing testing in
other areas during the next couple of days.
It would be a help to us if we could coordinate testing with you. We have remote control of
both transmitters. If you were available to work with us, we could shut them down one ata time and determine which of them might be causing the problem.
We thank you for letting us know about this, and we want you to know that we take this problem very seriously and aim to fix it promptly.
Could you please give me a call at the number below?
We’d be grateful for your further help, as we are for the effort you’ve already made to contact us."
Nice to see someone care for a change (though, I assume the idea of the FCC and Coast Guard being contacted might have expedited the response!). I'll post the results of the test.