> Boats, especially the larger ones you see being used for fishing/shipping generate a lot of noise due to powerful engines and underwater cavitation caused by their propeller spinning.
A couple of things. First, that video shows you how relatively quiet the ships are unless you are right underneath the back. You can’t even hear the engine noise towards the front of the ship (which is likely why a ship the size of a city block snuck up on a scuba diver).
Second, propellers on those ships don’t cavitate unless they are misconfigured. Cavitation is inefficient and causes vibration the shipping companies are absolutely incentivized to eliminate.
There are many problems with commercial shipping (the pollution, etc), but the noise is not realistically one of them.
The much bigger noise problem is sonar.