Having dealt with both Northwood Opcon and Ascot Ops there is no real difference between the 2. As other posters have said, if you have a problem, present them with a solution as well as the problem and they will run with your solution.
The difference, in my perception, is that in the maritime world, Opcon is reacting during a flight to an immediate set of circumstances which the Captain has to inform them off. With Ascot they are looking at a longer term position normally generated between sorties.
As a former maritime captain
I can honestly say that whilst going round in circles on the Malin Head or in the Swapps at silly times, my only reaction to hearing an Ascot callsign has been one of envy, or in in the case of a heavy C-130 at FL200, one of sympathy for the time it will take them to reach landfall to the west
