Week nine is the one nobody is ready for
The centrifuge is fine. The pool is fine. Then comes the day we take the lights and the certainty away.
By week nine our passengers have spun in the centrifuge until three G feels like a chair, and they have flooded and exited the capsule mock-up in the pool until it is muscle memory. They think they are ready. Week nine is where I find out who actually is.
We do the egress at night, in chop, blind
The real ocean is not the pool. It is dark, it is moving, and the recovery you rehearsed in daylight now has to happen by feel. We brief it honestly: nothing here can hurt you, the safety divers are an arm away, and you will still be frightened, because fear is information and we want you to meet it on the ground and not for the first time at sea.
The point is not toughness
I am not trying to break anyone. I am trying to give them a memory of staying calm when it counted, so that if anything ever goes sideways on a real flight, the body already knows the answer. The passengers who struggle most in week nine are almost always the steadiest in orbit. They have already had their hard day.
The ones I worry about are the ones who breeze through. So I make sure nobody breezes through.