I was the sonar officer and the enlisted guys went to so many schools before coming to the ship most were e-4s and had 6 year enlistments to start off if you can believe that.
In those six year reserve programs with two years active, the enlisted attended monthly drills for a year, and also attended a two week boot camp and a two week additional training, and went on active duty roughly one year after enlisting. If they went to further technical schools, they did that on active duty, and some of the longer schools required that their active duty be extended beyond two years.
Those programs were available during the Vietnam era and into the ‘70s. I’m not sure how long they continued.
Hmm, my cousin's son is an E-5 ST(G), and that's correct, he made E-4 before he got his ship. He went through his "A" and "O" schools down in San Diego ...... seemed like he was down there "forever" ...... he didn't get the "Green Door" course at Fleet Sonar School in Key West, where I went in 1970, but he's riding a ship right now on a six-year hitch. And, I might add, looking at the economy with a fishy eye, as he starts to look ahead a bit to getting out in about two years.