There was NO TZ episode about a lost sub.
“The Thirty Fathom Grave” is episode 104 of the American television anthology series The Twilight Zone
https://www.imdb.com/title/tt0734678/reviews
The sailor was so panicked I doubt if he knew the difference between “They’re, They’r and There” at that time.
At least “I” remembered that episode after sixty years.