There was a thread many years ago on the Dope where the Op felt it was very important that people knew that
"Man has visited the deepest part of the worlds oceans, Challenger Deep in the Mariana’s Trench, just once. In 1960. For 20 minutes. "
This turned into a joke thread apparently and then a SDMB in-joke that is used just often enough to confuse any new members.
I have a link to the thread at home, if you Email me, I will Email it to you tonight.