Dancing Hoskuld
Deity
It is a "feature" of RoM since v2.7 or so. It makes no sense at all to me. According to Zap it works the same for human and AI, but it sure feels like the AI has the advantage.
I use Aforess "A New Dawn" modmod package, It has a Seafaring option which sets it back to work the way it should be working.
The AI has an "advantage" because it spams ships and only one will sink a turn. Meanwhile you are building other stuff, that's your "advantage".