Almost like tinnitus, then?

You get used to it. It drives you bat s**t insane at first, but you get used to it. At times, your even able to tune it out completely.

Anyone who complains about a noisy light ballast should try having tinnitus sometime. I'll bet they'll take their humming lights with a smile.

Water makes a wonderful insulator, RF noise doesn't propagate under water. Unless its a fairly loud audible sound or creates a large magnetic field a single lamp ballast would be invisible to any detector not within a few inches of the source. The ships generator is barely detectable by OUR guys.

Of course the 'black hats' may have come up with something that nobody knows about, remember they can see the printing on a matchbook cover on earth from an orbiting satellite.