The best ASW training is prosecuting an actual submarine. US nculear submarines are unsuitable for use in this training for a number of reasons. First of all, US nuclear submarines are extremely quiet and thus poor surrogate target for the noisier Soviet Navy subs. Also, it's not a good idea to teach the Soviets how to conduct ASW operations against US submarines. Finally, the US nuclear submarine is generally too valuable an asset to be used in one on one training.
Fortunately,there are a couple of options. The US Navy commissioned a number of diesel-electric submarines in the 1950's which were still operational in the '80's. These were made available from time to time for training of US ASW assets. We were lucky to have USS Barbel available for several periods during our Kadena deployment. Crew 13 was scheduled for one of the training periods, which went of without a hitch, though details of the mission may still be sensitive.
I was also named to fly as Tactical Coordinator for another crew the next night. This mission was also going well when the radioman said the tactical support center wanted us to contact them ASAP. There was a difficulty. We were under orders not to break EMCOM (emissions control) while while in contact with the submarine. So we had to break off contact and exit the operational area. As it happened, the supposedly urgent message was to inform us to maintain EMCOM! I was not happy. We had to drive back to the op area, where we were fortunately able to regain contact quickly and compete the training exercise.
USS Barbel, first of the "B-girls"