Annoying things, for me, involving ships:

1. AI has so many small fleets, one ship fleet, that literally chokes the straits and u cannot pass them

2. ability to "blokade" a port with just one ship - just think at the idea, blockading the whole Cartagina port with a roman bireme, even the rats on that roman bireme would laugh to death

And I also agree with people that say "navy battle belong to another game" thing ... if that would be implemented, u would expect graphics to be at least of the level of, let's say, "Pirates of the Caraibean" ...

go ask CA hire Akela guys and problem is solved