[Chuckster]

In Navy slang, a “boomer” is a sub.

That only works if each "BOOM" represents a launch. Missile subs are called "Boomers", not all subs, IIRC

[EMI_Guy]

Yes...nuclear missile subs are called “boomers” represented by Ohio class boats. Attack subs, ones that can hunt down and take out boomers, are called “killers”. Los Angeles class.

New classes of these types may exist. I’m going on Tom Clancy info. I thank him very much.