How much do you open your tank valve?

[Darya3018]

When I got certified for diving, the instructors told all of the students to open the tank valve completely, then turn it back 3/4 of a turn. I thought this was the norm, and I trusted the dive instructors, but I've seen online that this practice isn't actually safe! Is the tank valve supposed to be completely open, and were my dive instructors wrong? I've done some dives since my certification, and I haven't experienced any problems yet, but I want to be safe for future dives.

 

[Jim Lapenta]

All the way on. The 1/2 to 3/4 turn back was due to old valves where they would get stuck in the open position. Modern valves don't have this problem. Open all the way until it stops. Don't crank it hard open. And don't let anyone touch your valves but you and maybe a highly trusted buddy.

 

[Marie13]

All the way. Period.

 

[islanddream]

All the way. And I make sure to enlighten the divemaster that I've already turned my tank on.

 

[northernone]

I personally do it all the way, that's either on or off. No change in breathing if all the way minus 1/4 turn. All closed plus 1/4 turn can breath on the surface and won't provide enough air at depth. That is a risk factor I don't need to add by an no longer needed valve care technique.

Some boats like 1/4 back because it's easy to confirm the tank is open (occasionally 90% closed if a mistake is made) before tossing the divers overboard. Divers often forget to open the valve even if they assure the DM it's open.

 

[shurite7]

Open all the way. The quarter or three quarter turn comes from the older pillar valves which many divers are not familiar with. When someone asks me if it should be open all the way or turned back I reply by asking them if they would prefer to breathe with no issues or struggle to breathe. The response is a bit of an exaggeration, but it drives home the point.

Alec Pierce has a nice video regarding this topic.
Go to 5:07 and listen to the explanation.

 

[northernone]

Loving this video! Thanks for sharing

 

[a878bob]

Nice !

 

[BoltSnap]

Open all the way and no turn back!

 

[scrane]

Open all the way then back a crack. Tradition is comforting in this crazy, modern world.