[Freeflow]

I prefer the Apeks low profile shoulder dump. Dunno why just do.

When I was taking people in after they had done OW and then bought a DS with a shoulder dump a lot seemed to struggle, so I developed this method to help them out:

Open the dump all the way and drop to at least 5m [but no more than 10!] using the BC for buoyancy control.

Empty the BC and fully close the DS dump.

Do a pin fivot while adding air to the DS.

Now go into a hover.

Drop back to your knees and then slowly open the valve. When bubbles come out close it a click or two.

You should now auto vent the air on ascent as the pressure in the suit becomes greater than the water pressure.

On the surface count the number of clicks to fully open or closed, that way you can set it if it gets knocked.

Make sure you do the above with a buddy who can help you if things go wonky, and get you back to the bottom from the hover if needed.