Lock-out can be accomplished mid-water by a PSUB but the real question is it safe. The commercial subs (large PSUBs in many ways) determined that it was very hazardous for a number of reasons, biggest of which was there were deaths encountered in early mid-water lock-outs..
If it was your PSUB that was responsible for a mid-water lock-out death, would you want to be the one to have to inform the diver?s family that it was your sub and procedures that caused the death. You would also be responsible for negligence in the legal form since the prudent person would not do a mid-water lock-out, that community practice does not support mid-water lock-out operations, and knowing this you still committed the act the 3 proofs necessary for negligence). Any English-speaking general
court will find you guilty as well as any maritime court in the world. You can do mid-water lock-out but the burden is on you.
R/J2
Respectfully,
Jay K. Jeffries
Andros Is., Bahamas
A skimmer afloat is but a submarine, so poorly built it will not plunge.