Question for Instructors

I have a question about the current instructional practice of opening tank valves.

Back in the day, divers were told to open their tank valves all the way and then back off 1/4 turn. The reasoning was so someone could determine an open valve from a closed one.

I've worked with an instructor recently that is teaching to open the valve all the way and don't worry about the back off 1/4 turn. Reasoning being that the valve seat doesn't wear out as much as previously thought.

What are you instructors teaching? Is this a standard practice across all open water certification agencies? And does it matter?

Thanks!

I teach all the way open with the admonishment to boat crews to keep their hands to themselves and don't touch the valves. the valve seat is one reason I heard and also that DM's on boats will verify if a tanks is on. If the valve is all the way open then they may make a mistake and turn it off. If the DM is that dumb he better not be touching anything of mine and and it is the divers responsibility to check his/her gear along with their buddy. If they can't or won't do that they should not be diving.

I had an "insta-buddy" turn my tank valve off by mistake last week. SInce I couldn't reach it I had the boat captain turn it back on. Scary.

Greetings riskill1 I am just a DMC but the instructor I assist always emphasizes to open your tank valves all the way! The reasoning behind this practice is that if someone mistakenly shuts your air all the way off, you will know hopefully before you enter the water. If you do enter the water you will know it before you descend.
If you practice the old all on back a 1/4 it is possible to think your air is all the way on but in reality only a 1/4 on. Your reg will breath until the ambient pressure builds. This leads to a OOA situation at depth. This happened to me in Mexico on a dive boat and was not a deal breaker but did make me determined to have a serious talk to the boat hands.
If the tank is all on you can reach back and double check it your self, I have gotten into this practice ever since. I know many others who still do the all on back a 1/4 turn but I choose to follow my instructors guidance and leading. I am sure you will get some for the opposite but that is ok. You need to decide for yourself. It just makes sense to me to go all on.
CamG Keep diving....keep training....keep learning!

Thanks for the input.

I used to teach the 1/4 turn back (old school). I have switched to full open with two breaths on the reg, looking at the SPG before you go jumping in the water. Look for the needle to move, if it goes down, the valve is off.

All the way on. Purge blast breath while looking at your guage. I watched a DM on a boat turn the tank off then on 1/4. I of course said something to him and the diver.

For new OW students during my DM interns(or AOW students that've barely completed their OW) I'll go around giving everyone a turn to the left.. A not insignificant portion have barely opened the valves a crack(1:5 instructor/student ratio, it always seems like at least 1-3 people will have have missed this).

If you're certified I'll ask if your buddy checked your tank first before grasping at it.

(If it does turn too much I stare at the valve and make sure I'm not closing it.)

I was taught to open up and then back off a quarter turn, now that I am an instructor I teach to open all the way, like CamG I had a buddy who had his air turned off then turned on a quarter turn on accident and like CamG went OOA at 25 feet or so, lesson learned early on....

I for one will still teach the 1/4 turn back off. I was taught that the reason for this, in any similar valve use, is to limit the damage from opening it strongly when it's already open. When a valve is all the way on or all the way off, it is often hard to move in both directions. If it is all the way open and someone with good grip strength checks to see if it's open, they may crank it in the open direction strongly, thinking it closed, causing damage to the threads/valve. If it moves a little and then stops, no need for the strong crank, just turn it back to where it was.

Many posters here on SB seem to be OCD about other people touching their gear. It's only scuba gear, it survives airline baggage handling, if a DM manages to break something it was not in great shape to begin with; better on the boat or at the beginning of the dive than at depth on the dive. With regards to DM's and Captains turning divers air all the way off as they left the boat; If the 1/4 turn back off was enforced at least it would be 1/4 turn on.