A simple convoy system, two escorts (each equipped with at least one helicopter for a rapid response).
The vessels meet at a pre-determined formation point and time then disband when a safe distance away.
The two escorts pick up the next opposite direction convoy at this point and so on and so on.
A simple system of half a dozen countries agreeing a rota for the supply of two ships each for a given time.
This could/would also be beneficial to all participating countries as a training aid for joint sea ops.
Failing that.....Q Ships...BE MORE AGGRESSIVE!!...SINK EM ALL!!