I'm curious about the US doctrine for anti-shipping attacks 25 years ago -
say, the late 70's/early 80's?

What were the weapons to be employed to lower the target below sea level?
(I'm not so much interested in the use of ARMs, but rather the
larger-explosives designed to let water in or start toasty fires.)

For example: In the Falklands, the Argies used gravity bombs, delivered
from low-level in daylight. Would the USN have employed the same weapons
and in the same way?

[Yes, there were a couple of Exocets too.]