I didn't find anything about the potential effects on marine life.
I'm not in the market for this, so maybe it's obvious to those who are, but it would be nice to address it somewhere for the uninitiated.
But their modem[1] uses NATO's JANUS standard[2], which communicates at 11.5 kHz, which is just audible to humans, but well within range of marine mammals[3].
1: https://www.subseapulse.com/products/ 2: https://spectrum.ieee.org/nato-develops-first-standardized-a... 3: https://en.wikipedia.org/wiki/Hearing_range#/media/File:Anim...
For underwater acoustic systems there is a well understood and effective marine mammal mitigation process that’s followed. Basically, slowly stepping up in power. Not sure if they’re employing that here but if it involves NATO, I would expect that’s being employed
Imagine someone set up a radio or a noisy machine somewhere in your own vicinity and you had no choice but to listen to it (even at a low volume) all day and night, perhaps for the rest of your life. Tests might or might not show that you were stressed, but you most certainly would be.
Perhaps I am biased from regular snorkelling and enjoying being immersed n a different natural world, and for sure I do have tree-hugger tendencies. But I find it extremely arrogant that our species thinks it's acceptable to inject noise pollution into an environment inhabitated by thousands of other species.
All that to say, I certainly understand the concern. But I would personally have to see evidence of harm