I don’t know about the AIS being off...I am an Airedale! But I gave it some thought, and using standard military logic...I would think it would be off by default when at sea.
I would have thought that to be the case because...why transmit movements of our ships? Why give our foes real time data as to where are ships are and what kind of ships they are?
But as you referenced in another post...the Navy has indeed changed its policy on this, and I don’t think you are giving much away. After all, in crowded sea lanes, there are a lot of eyes that know just who and what you are.
I bet they don’t have AIS turned on during operations outside those crowded sea lanes, though.
Both Fitz and McCain were in areas where I'd definitely have the AIS ON, if it were my call. But in Op areas, I'd definitely shun making my ship a located target...