FWIW: what I could gather at today's practice race - they are using Marine VHF CH 81A, 82A, and 83A for the Coast Guard Port Operations. CH20 broadcast the race announcer's feed. My Uniden scanner picked up a lot of near field (Close Call) digital noise in the 170 - 176MHz range.
I was scanning those frequencies also and had heard a lot of digital noise, but it didn't register as near-field on my scanner
I read somewhere they were using some sort of text based system, so that must be it. I can't imagine typing on a touch screen would be very easy as your racing through the waves at a 45 degree angle - but perhaps they're sending some sort of engineerring data.
I did hear TV directions to camera op, talent, etc on 478.700 NFM. I also heard announcer's audio on 479.200 and 479.400. Mostly on-air stuff, but some pre-show banter.