There are good and bad points of both services. Good in the RN and bad in the RAF hee hee!! Seriously though take the advice and leave it as late as possible to make your final decision.
The POAC course involves visiting the Squadrons, lectures on the Fleet Air Arm and you should get flying too in at least one type down there. More importantly you will get to talk to the guys and girls doing the job and not someone paid to recruit you, if you like what you hear well than that's your answer. As for going to sea, yes the shine can wear off it after a while but waking up in a different place every day can be good fun and if you are young and single then it's a great life. Good luck with whatever you decide.
Fly Navy, Dig Army, Eat Crab