Scuba Diving makes you faster.
Scott "yeah she suffocated"
Kevin "Suffocated? Don't you mean drowned"
Especially effective if the Japanese man is only half Asian, as he will be less vindictive in the case of resurfacing.
The term comes from the idea that the reason why the person is in the bathroom so long is because they're literally swimming around in the toilet water rather than doing their intended business.
George: I know, me too -- what the hell is he doing, Scuba Diving in there!?
Roger: Damn it, I got to shit really bad, but there's only one available stall in our building's men's room, and some damn old guy's been in there for ages with his newspaper. God damn it, I hate Scuba Diving!
Jason: Dude, we've been waiting for a fucking long time to go and pick up our pizza. What the hell were you doing in there, Scuba Diving?
Tom: Nah brah, I got the Farmville app!
Ben: what did she do
Dom: she wanted me to go scuba diving in her
Ben:shit thats fucking nasty