Sandanme: Dangyo no Fuchi

is a technique of Shunsui Kyōraku's Bankai, Katen Kyōkotsu: Karamatsu Shinjū.

Description
A massive amount of water engulfs both Shunsui and his opponent, who remain within it until one of them runs out of Reiatsu and drowns. The body of water is inescapable; attempting to swim toward the surface will only result in being pushed further down.

Shunsui poetically describes this technique as "Having prepared themselves for their fate, the two throw themselves into the gushing water until their Reiatsu is no more."