Boomer

Boomer is US Navy slang for a ballistic-missile submarine, hull symbol SSBN, the leg of the nuclear triad that carries submarine-launched ballistic missiles on deterrent patrol. The current US class is the Ohio (SSBN-726 series), each carrying 20 Trident II D5 missiles after New START reduced the loadout from 24. A boomer’s job is to stay undetected and survivable so its missiles guarantee a second strike; this drives the dual blue/gold crew rotation and continuous patrol cycle. The successor Columbia-class begins replacing the Ohios from the late 2020s.