In Poland we have a drink that's quite popular among students (however the really most popular is the "mad dog" one). The drink is just a glass of beer (that half a liter kind of them). Before you start drinking it, you drop a small (100 ml is max) glass of vodka (40% up to 95% alcohol) into the beer glass, so that if falls slowly on the bottom, but the vodka does not mess with the beer.
And you start drinking. The more you drink, the less the beer is still beer, and the more it becomes vodka. Marvellous.
And that drink name is: "U-boot".
PS And we call it "u-boot", in German, not in Polish (it would then sound "okręt podwodny" and that's a bit too long for a drink name. One would have trouble trying to spell that after having a few u-boots...).