I sure would not want to be anywhere near the opening if someone opened a 12" valve 40' under water. It might be the divers last dive.
A 2-4" open end might be manageable. A 6" open hole operating at 17 psi negative pressure would be dangerous. Anything bigger and being within two or three feet of it when it opened would likely be fatal if it opened all at once.
Diving around lake dams always made me nervous. I know we were a quarter mile away, but you could still hear those turbines plain as day and they were not quiet under water.
Last edited by snrub; 11/14/17 11:44 AM.
