Spent 3 years on a fast attack sub and can attest that though difficult and frustrating at times, life on a sub is indeed interesting.

One of my favorite tools onboard was our sound speed profiling software. While it was often wildly inaccurate compared to what we were "seeing" in sonar in real-time, it was fascinating trying to predict what we would and would not hear.

We definitely picked up MODUs (Mobile Offshore Drilling Units) form thousands of km away.

Also, there are many older submarines still out at sea, and many of them don't use sound dampening tech (i.e. rubber grommets) on their noisy gear (pumps). Pretty loud too.