Here's a nice article [1] on underwater sound in extreme storms, note in the referenced paper [2] they managed to deploy a hydrophone under 10 m waves and 40 m/s winds! This type of research is largely military funded, not for its direct applications but more because sound is so fundamental to everything a navy does. There are also civilian applications for measuring waves, wind and rain, either in extreme conditions like [2] or where a surface buoy is impractical (e.g. in locations where surface buoys tend to get stolen or broken). It's definitely a case where one person's "noise" is another person's "signal". I too am a bit surprised saildrone didn't have a hydrophone on their rig, maybe they did but the sound is not so interesting for the press release.
[1] https://acoustics.org/what-can-we-learn-from-breaking-wave-n...
[2] https://journals.ametsoc.org/view/journals/phoc/44/10/jpo-d-...