I keep having AI fleets sail right through 2 fleets of mine. Its driving me nuts I been chasing a Austrian AI fleet for 8 turns now with 2 seperate fleets of mine. The dam fleet hit 5 trade nodes already. I caught them once and they retreated so far out of range it took me 3 turns to catch back up had them cornered and they sailed through it. Its not just Austria tho its all nations I'm at war with.
The only time zone of control works with fleets for me is when I blockade them in a port and use a army to knock them out.