A Cage used exclusively for the Eva. Only the head of the Evangelion emerges above the water's surface.
Ritsuko:“This is the Ultimate All-Purpose Humanoid Decisive Battle Weapon developed by humanity. The artificial human, Evangelion. That is EVA-01.”
Reichu: One thing that's puzzled me is how the scripts refer to virtually any liquid in NGE aside from potables or (most) bodily fluids as “water” (mizu). (The scripts even describe LCL as water!) It's never actually stated AFAIK, but it was my understanding that this pink liquid is actually coolant used to“refrigerate” the Evas in conjunction with the B-Type Equipment. As for what this “B-Type” stuff is all about, we'll get into that later.
Considering the sheer amount of coolant in this room, I would've expected the characters to exhibit some degree of environmental discomfort. I suppose it would have detracted from the drama to have Shinji whining about the temperature (in addition to everything else he's going to be whining about in a moment ;;> ), but we never hear the characters gripe about this is any other Cage scene, either.
“Artifical human” is a literal translation of jinzou ningen, which I've also seen translated as “android”, i.e., a human-shaped automaton. Since the Evas basically are treated as little more than automatons, I suppose “android” would be a fitting translation, although I prefer the ambiguity of “artificial human” here. “Artificial” is merely the antithesis of “natural”, which EVA-01, being a product of mad science (= human craft), certainly is not; and Ritsuko will refer to the Evas as “human” later on. So, in theory, jinzo ningen could be interpreted either way (unless, of course, such ambiguity does not actually exist in Japanese usage, in which case I'll retract my comment).