Didn't someone once talk about putting something like Rapier on the top
of a submarine periscope to knock down impertinent helicopters?

SLAM: a cluster of Blowpipe missiles around a TV camera for aiming. Went
to sea on HMS Aeneas, trialled, and failed to proceed: having to come to
periscope depth and stick a large mast up turned out to be a bad idea
when armed ASW assets were buzzing around.

It's often reported Kilo class subs have similar capabilities built
around Strellas and Iglas.