Bouncing Zabaglione Bros.
Legend
Complete fluid immersement for increased shock resistance (as opposed to pressure resistance like in the abyss) is featured in Neon Genesis Evangelion for example.
First time I remember reading about it was in Joe Haldeman's "Forever War" and that was published in 1974!
It's used by the soldiers while their spaceships are manoeuvring at high gee during military engagements. The soldiers have a couple of valves implanted in their bodies and they are filled with fluid both internally and lie inside flooded tanks and body shells while their computers run the ships during high-gee battles.