Some submarines have carried surface-to-air missiles for protection, especially while vulnerable on the surface during other launch procedures. Underwater-launched anti-air weapons are generally short-ranged and receive limited targeting information. They are more useful for disrupting a maritime patrol aircraft and buying escape time than for reliably destroying the aircraft. Launching one also reveals where the submarine is, potentially converting an uncertain inference into the confirmed contact that attracts more ASW forces.
Notable Point · 47:02-48:21
Why submarine air defence can reveal the boat
See why launching an anti-air missile may help a submarine escape yet turn an uncertain contact into a confirmed position.