I can categorically state that I have never run one of HM submarines aground, does that help?
No, not really, since your "statement" tells me nothing about your background, and I certainly didn't miss the fact that you seem to be unaware that ships and submarines are referred to by those who know them as "she" .....
Jack
(who has conned warships from a frigate to a fleet carrier and, oh yes, a "very large submarine" at BUTEC)