andym said:It used to be either Subs OR MA(RN CDO) it may well be the same.Once they have trained you for Subs they will want some return of Service for it.If you want your Green Lid you may be best to stay MA.
There's a Submariner Sigs bloke up here in Faslane at the minute who is going for 148 Bty and is about to go down the route of RNMAC, AACC, etc. Apparently it is possible but the 'line managers' are very negative about the whole issue.
I say go for it. Get as much from the services as you can and make the most of your time while in. Noone will give you anything, you've got to take it for yourself.