Blue Submarine No.6 is a pretty badass anime about the once famous and well respected scientist Zorndyke who has bred a new genre of living being, one that thrives on the oceans and lives to destroy humans. Zorndyke believes it is time that the humans were relieved of their rule of the earth. It is up to Blue Submarine No. 6 and the rest of the Blue fleet to put an end to Zorndyke's madness and creations.
A feacal deposit left in the toilet bowl following an unsuccessful flush. Due to the density of human excreta these visual obscenities usually reside at periscope depth. Simple post-flush checks by the degenerates that leave them behind would render the Brown Submarine a thing of the past.
Bridge Officer: Captain! Bearing 030 off the starboard bow. Brown Submarine!
Captain: Set Depth Charges to Zero...Fire 1...Fire 2...
"Watching the submarine races" is a euphamism for making out (and more) in a car. It's the kind of thing a cop would say to be funny when he knocks on the fogged-up window of your chevy parked in back of the safeway to ask what you're doing there at 1am, as if he doesn't know damn well.
Cop: Hey, what're you kids doing in there? Watching the submarine races?
People in car: Gak! Where are my pants?