Any 1st stage can be left sitting in water. Just depends on how much you trust the dust cap to seal.nice tip on Z3 I was thinking about the swivel.
I have only used my T3 a couple times but I think the warnings said do not immerse fully in water. My apeks I would just let sit in a tub of water. Atomic warned against this it seems? Was that only due to the second stage? So you CAN immerse the 1st stage in a tub? Im not an engineer obviously, this is all greek to me. I sell products not make em ha.