If you are prior service you can get back in the guard at almost any age. If you really want active duty, then transfer after you are in the guard.
If you are older than 42 join the naval reserves, they have some sort of program that you can join until you're like 100 or so. A 3 or so week book camp, no joke. The you do the Army's "Blue to Green" program which is also real short.
It's good to already be able to do a 210 or better APFT before you join (better yet a 270+), but believe it or not, Basic is Basic. You'll be surrounded by 19yo who have never done anything and can't do a single pullup. Three months later you'll be doing good.
I know two guys that in the last year graduated the SF Q-course at 41 and 44. (one has 3 kids , don't know about the other one) Both had a 15+ year break in service.
I know a guy who is 50 that is putting in his packet for SF this year. four years prior service 20+ years ago, now successful with a kid under 5yo. Rejoined and is going to push to be allowed to go SF.
I know a guy that just had leukemia thats going back in, he's just not going to tell them. Screw'em if you want in, make it happen. BTW that guy makes $200,000+ a year has a young kid and told his wife if he gets activated they may have to sell the house and move to a smaller one.
Every one of these guys has hearing waivers, pins in joints, surgeries, etc, etc.
I know all these guys, not heard of them. They all serve in my unit. The average guy in my unit is >40, with a family and kids, with a job that pays more than the military, coming back after a 10+ year break in service. All these guys have done a one year deployment since the war started and half have volunteered for a second tour which they just finished. To my knowledge not a single guy has lost his wife over this. They all got over it and got with the program.
I was lucky, I came back at 39 but have all my quals in order so I just had to show up again. I have surgeries and shit that would need waivers if I needed schools, but I've already done them so no big deal. No wife, no kids. After Sept11 I took one year to get my finances in order so it wouldn't kill me. Rearranged my business, got rid of my house, sold everything extra.
That why some of us get a little short when everyone wants to publicly tell us all the reasons they can't serve.
No excuses!
Either serve or don't. If you want to serve either for the first time or again, speak up, and some of us will tell you what we know.
BTW my buddys unit just rotated back and they had a guy who was >55 and a vietnam vet. Before they went over he had to tell his VA PTSD counsellor he wasn't going to make his sessions for a while!!!!! Do you call that a setback!!! They made him the motorpool sgt, he did great and had a blast.