You mean know where the enemy CV is at all times no matter where on the map?
Yes
.
What
???
If someone takes off from a cv, a Dar Bar shows up, no matter where the cv is. On the premise that a Dar Bar represents someone seeing a plane and reporting it, it is very unlikely that someone would see a plane in the middle of the ocean because it would be unlikely that the "reporter" and the plane would be in the same, empty, vastness at the same time.
What should be the case, however, is, as a cv group approaches the shore, it should trigger the base radar and city to flash.
After all, the Doolittle Raiders had to launch early,
200 miles off the coast, (yes,I know, scale), because they were spotted by a fishing boat and feared detection.
You can argue that Japan was still not warned but I would respond that they ignored the obvious. Tokyo was flashing.
Otherwise, no, you shouldn't be able to know where cv's are at all times. Even if someone is in visual range. That's what player communication is for.
wrongway