Re-Qualify for new subs?

[CaptBones]

It depends on what you mean by "qualify" to start with. It is also very different with respect to the specific circumstances of a Commanding Officer of one boat taking command of a new boat.

"Qualified in Submarines" means just that...qualified to wear the dolphins and to serve aboard any boat (and to collect the additional pay that goes with that qualification).

"Qualified" to fill a specific billet and stand watches aboard a specific boat is different...you have to re-qualify for those each time you report for duty in a new boat (new to you, not necessarily new construction).

On the other hand, a Commanding Officer is "Qualified to Command" just once...and that happens when he gets selected for Command, attends PCO (Prospective Commanding Officer) School and successfully completes his first tour in Command. Normally...meaning in peacetime...a CO will leave one boat and take command of another (bigger - better) boat after an intervening tour in a shore duty billet and after going to PCO school again to get some "refresher" training/education in the specifics of his new boat.

But, in the dark days of WWII, that didn't always happen. A successful "Sugar Boat" skipper could "Fleet Up" to a "new" boat with not much more than a hand-shake from the ISIC (Immediate Superior in the Chain of Command) and the Operational Commander (COMSUBPAC or COMSUBSOWESPAC). There was no re-qualification required beyond a "PCO Patrol" in his new boat before taking command. See Part 3, Chapter 2 of "Wahoo..." by Dick O'Kane.