Four (or Six) Fast Attack Submarines

(Four in Google, Six in Bird's Eye View)

Probably Los Angeles Class subs. The LOS ANGELES class SSN was designed almost exclusively for Carrier Battlegroup escort; they were fast, quiet, and could launch Mk48 and ADCAP torpedoes, Harpoon Anti-Ship Missiles (no longer carried), and both land attack and anti-ship (no longer carried) Tomahawk cruise missiles. The new submarines showed another step improvement in quieting and an increase in operating speed to allow them to support the CVBG. Escort duties included conducting ASW sweeps hundreds of miles ahead of the CVBG and conducting attacks against the SAG.