What if you need to use some of that 500 psi contigency reserve?

[engdiver]

One other thing to consider is what your SPG is actually telling you and what pressure is still in your tank. Many SPG's (mine included) read 100 to 200 PSI lower then actual tank pressure. That adds up on certain tanks such as what Stu S mentioned above. 200 PSI is more than 5 cf on a steel 72 cf tank. More on larger LP steel tanks.

 

[northen diver]

Well your lack of experience is showing! I decide based on if your in control and if your calm! I would rather drag you to the surface and resuscitate you than kill myself with a panicked diver! In life guarding you are taught to take a drowning victim down until they submit. I don't know your level of training! So if I am low and your out we do an emergency accent! I will control the air! If I am in control I will decide all the management of your rescue! It is the price you pay for using all your air up! I have investigated dead buddies who died struggling over the rescuers regulator! So before you charge in and give someone that was not trained like you YOUR AIR!

And when you have a 1000 dives speak up Mr. 100 to 199 been diving a year! Glad your getting entertained I hope you get educated!

This is simply not true. I had taken the ARC, YMCA, BSA and the USLA gaurding courses and ALL of these angencies will teach different escapes which DOES not include taking a victim down until they submit.

 

[captain]

When I learned to dive we used J valves that kept 500psi in your tank to come up with! No gage! When you started to breath hard you pulled your reserve! No big deal, and we didn't do safety stops either, and no one died! The only reason to bring back 500psi is that's the operators policy and two you should have positive pressure to keep water out of the tank. it's still 15% of your tank! On the surface it's probably 10 to 15 minutes air! I have sucked a few tanks dry! But remember the volume in crease the most in the last 10ft to the surface! If you are on the surface and have a problem manually inflate your BCD if you have to! Drop your wight belt! Take off your tank and sit on it! If its aluminum it will float along with your BCD and if the BCD won't hold air the tank will float! So I don't know what emergency you would have that would require SCUBA gear that you couldn't do in snorkel gear? Many times I have taken my gear of in the water many times and handed it to the boat! So the idea is to have positive pressure in the tank and be safe! Remember a SCUBA diver without a tank is a swimmer! Can you swim?

Actually the J reserve was 500 psi on the doubles manifolds so when you pulled the reserve the tanks equalized at 250 psi and 300 psi on the single valves.
A lot of my diving is solo so I only have to plan for gas for myself. I have started up from 80 feet with 200 psi many times. In 20 or 30 feet of water I'll take a tank down to 50 psi or less.

 

[GrumpyOldGuy]

No offense intended, but over confidence in ones abilities is very dangerous no matter what your skill and experience is. Being at 80' with 200psi or anytime with 50psi would make me sit down and totally reasses my dive plan and upate my will.

 

[captain]

IMHO, you would have to take the first stage off, open the tank until it makes no air escaping noise (actually empty)and then submerge the open tank to get water in it. Perhaps this would be a good question to ask Myth Busters!

I have to pretty much agree here. About the only way to get water in a tank while on a dive would be to breath it empty on the surface and then take it back down to depth while pressing the purge button.
Most water gets into tanks diring the fill process, either water from an improperly maintained compressor or water blown in because there were water droplets on the valve or whip when it was hooked up.

 

[captain]

I have sucked every drop out of a 72! Sucked it negative and if you open the reg it will pull water into it! In the 72cft J valve days sometimes they got pulled down in kelp! I have run out at 60ft! Panic kills not out of air! A little more at the knee please!

Key part of this. "if you open the reg "

 

[captain]

No offense intended, but over confidence in ones abilities is very dangerous no matter what your skill and experience is. Being at 80' with 200psi or anytime with 50psi would make me sit down and totally reasses my dive plan and upate my will.

Anything can happen at anytime to anyone. Maybe I''m lucky and sooner or later it will run out but at 63 years old it's lasted for 50 years of diving and over 1000 dives. I have never run out of air, had and equipment failure or a dive related injury other than cuts and scapes.
The two potentially fatal incidents I have had in my life were in an automobile and a military aircraft and in both situations I just along for the ride.

 

[GrumpyOldGuy]

Anything can happen at anytime to anyone. Maybe I''m lucky and sooner or later it will run out but at 63 years old it's lasted for 50 years of diving and over 1000 dives.

I would rather depend on a dive plan and a reasonable reserve of air based on the dive profile rather than luck.

 

[frankc420]

I only dive HP tanks and if I'm below 80' I'll turn the dive between 1000-750psi.

On a 100' dive I've turned at 750 and ended the dive w/ a little below 600psi. That's with a 5 minute safety stop. If I'm above 60' I'll get my tank to 300psi.

 

[Papa_Bear]

Captain, thanks for the post! Let say I find this very interesting and I am amazed at the attitudes especially about ones own safety! I must say I have read here about people expecting out of air divers to be "Calm" and well trained! I think they need to learn about the story of the Scorpion and the Turtle! In real life people who are drowning panic and do really stupid things. I am a YMCA WSI and was a full time Life Guard and the Aquatics Director For The California Polytechnic University at Pomona for three years! I am here to discuss and help because I am passionate about SCUBA and every aspect of it!

BTW that's why I do the! And I know it gets a few excited! LOL I have dealt with people for many years who put form over substance and they come out here and you get to see who they are! Some just act as if the were kicked in the head once too many times! "Let a man be known by his works" heard that some place! I am here to exclaim my love for all things SCUBA!

Do I expect you to "See the Light"? No! Do I hope a small portion sinks in and makes you think? Yes! But what I hope most of all is Divers keep diving safely and new divers continue to dive and interest their friends. I want them to have confidence that it is a safe activity with basic knowledge and they can take it as fare as they want! I want them to love and enjoy the activity as much or more than I do!

For those of you who don't know what a Public Safety Diver is, find out! These people serve the community and many of them are volunteers!

Dandy, thanks! MF, you are the best quoter here! Maybe one day you will have an original thought? nd if you Guarded I am amazed your alive! Because you are WRONG!