Have a look at this website www.rncom.mod.uk - it may give you some answers. DH has in the past been issued with a welfare booklet, which I tend to ignore, as I sort stuff out myself.
The RN gives lots of the info to those serving. for them to pass on or not as appropriate. They are as good as they can be welfare wise, but sometimes they literally can't help, especially if your dh is on deployment; and it's also dependent where he's on deployment. My dh didn't know I'd had ds until 3 days after he was born, as he was under the water and not on it, and then they moved heaven and hell to get him from somewhere off Scotland down to Plymouth. The comment was that they were glad to do it, as on that occasion they could, but had he been on patrol, I wouldn't have seen him until the boat came back, even if it had sailed 4 days earlier.
The bottom line, and it's hard to swallow, is that the RN takes precedence over the families. I know it's tough, ds wasn't well when he was born; dh was back at sea; my in-laws and my mum were in Hampshire,(3.5 hours away), I was in Cornwall and we had a constant round of hospital and doctors appointments. You have to learn to deal with it on your own. It's effectively like being a single parent with another salary coming in.
I think by giving him a Plymouth ship they did the best they could. Rationale was probably that it's easier to get to Bristol and across into Wales from Devon, than from Portsmouth or Scotland. There's also the question of there being a billet for him on the university training ships. The RN is undermanned at present, and the guys have to go where they're needed; that's what they are paid to do.
What it really comes down to is that you married someone in the RN, and that means time apart either weekending or sea time. I've spent 16 out of 22 years either weekending, or dh being at sea. It goes with the territory. You have to decide if you can live with that, or if you want him to leave the Navy.
There are upsides as I said in my earlier post, and I can't imagine dh in one job for more than 3 years, as he would be bored brainless. At least the Navy move you around and you get wide and varying experience, and the chance to get qualifications as well that they pay for and not you. It's up to you if you move with him or not. I moved in 2006 for the first time since 1986, as we have our own home, and I had a job so I decided to stay put. My sil on the other hand, follows my brother around, unless he's at sea. Either way works, but you have to be happy with it, and you need to understand that Forces life is not like anything else.