The CAOD manual states that you will never be ordered into the Med, but you can sail into it and continue your career from there in La Spezia and Salamis
So you have to "volunteer" for the Mediterranean, or imagine that you have been given that order...
Ahhh that lovely CAOD....may be one day we will get a CAOD II with the SH3 graphics (Except the stupid cyborg crew, which kills all inmersion
)