> Pretty hard to hide from a satellite I'd imagine.

At one time I guessed that too, but I've heard navy people explain that it's actually pretty effective. Imagine saying 'pretty hard to hide in North America from a satellite' - it's actually not hard because the area is so large; there aren't live images of the entire area and someone needs to examine them. Oceans are an order of magnitude larger.

A significant element of security for naval ships is hiding in the ocean. US aircraft carrier planes have a ~500 mi effective radius without refueling; even if you see a plane, all you know is that the ship might be in a ~3,142 square mile area. And remember that to target them, you need a precise target and the ships tend to be moving.

With ML image recognition at least some of that security is lost. Also, the Mediterranean is smaller than the oceans, but the precision issue applies. And we might guess that countries keep critical areas under constant surveillance - e.g., I doubt anything sails near the Taiwan Strait without many countries having a live picture.