Fred J. McCall wrote in
:

[snip]

Before Harpoon fielded there were ships out there with a system called
ISM. It was essentially a modified Standard Missile fired in an
anti-ship mode and was put out there to 'fill the gap' until Harpoon
was available.

There are, of course, trade offs in using a missile designed to attack
aircraft and other missiles to attack ships.

Didn't the Talos system have an ASuW mode of operation.
I vaguely recall reading something about that some years ago.
The part that would hit the target would probably mass something
like a ton and a half.

IBM