Holy shit he broke Sanji.
This pool can’t be that deep, seeing as Genzo and later Nojiko are fine under there, so really it’s how fast the pressure is building that gets Sanji here. The rib-cracking effect and internal bleeding and all that is maybe even over-exaggerated here? Like unless somehow the two civilians managed to spend several minutes on the way down waiting and adjusting this would not be enough to kill you. Good divers can spend a few minutes at depths around 130 feet/40 meters underwater and I have to assume that even with anime bullshit science they aren’t going more than 200 feet down or so.
The main bit of ouchie would be in depressurizing, which has short- and long-term effects of oxygen sickness, dizziness and nausea. Sanji shows no ill effects at this, but if Kuroobi did this a few more times I think Sanji would have a harder time after leaving the water.
