I have an explanation for “submarine races” in racing category. In some areas of the US, when young couples wish time alone to romantically explore each other, they park their car in a lonely spot . . . and it is said that they are “. . . going to the submarine races . . . .”
Altho I have heard the expression many times, and having been a dull man on a date once (we discussed the computerization of the dewey decimal system), I cannot supply any photos.
That’s “racy” indeed. (Pun intended,)
After reading the racy paragraph, I felt such a relief reading the second paragraph. The computerization of the dewey decimal system certainly is a suitable topic for a dull man on a date.