Dive mode or +/- on regulator second stage

[DukeAMO]

A well adjusted regulator should free flow under the water out of your mouth if the mouthpiece is facing up. This is because the cracking vacuum should be about 1 inch of water, and the distance between the diaphram and the mouthpiece outlet is usually more than 1 inch.

Yes, my regulator actually free flows every time I take it out under water, and it won't stop unless I cover the mouthpiece with my hand or put it back in. Someone here suggested switching the lever to "-" before removing it underwater.

The training regulators don't usually do that because they're tuned to prevent it. That would freak out students!

I usually flood my octo and 2nd stage as soon as I get into the water, then put the octo into the holder. That will also prevent free flows. If you put the octo into a holder with air in the holder it'll probably free flow on you, or at least bubble slowly. I find this easier than remembering if I've flipped the switch or not.