I went from aviation to maritime some years ago now - some of the high speed ferries I drive are required to have a camera in the wheelhouse/bridge.
In fact, even some of the smaller slower boats I was driving had them on me (as pax would board in that area, so for security).
I just don't see the issue - if you're doing your job properly, it shouldn't matter. It gets recorded to a DVR and wiped after a certain amount of time - so its not like they're watched for the fun of it... They would only ever access them if there was a major incident (not that I have had any). On the few occasions I've heard about - the camera actually vindicated the skipper for doing the right thing.