Thanks for all of your replies everyone.
I m still finding it difficult to decide which is better for me to join. My school grades are excellent ( I m in the middle of exams this week
) and I am ok in terms of fitness (as in, I dont have any serious health problems....although I m slightly underweight at the moment) . I m thinking that the RN training would be more vigorous (as you're at sea) but I m not sure. Any ideas? It's also said that RN heli pilots can also switch to fixed wing later on, can you do the same with the RAF?