How many "major ships" and how do you define "major ships?" As far as I
know
no battlewagons, heavy cruisers, light cruisers or aircraft carriers were
sunk
by ASMs.

Roma springs immediately to mind - speared and sunk by Major Bernd. Jope, who
Hitler personally decorated for the act. To me, that would be a 'major ship',
as it was a front line, modern battleship. I have a small collection of things
from Jope, recording this action, including a photo of Roma's death throes.

v/r
Gordon
====(A+C====
USN SAR

Donate your memories - write a note on the back and send your old photos to a
reputable museum, don't take them with you when you're gone.