Rock Bottom psi..thanks for knowledge

[traumadiver]

Near miss to report, thanks to everyone for the knowledge on air management and rock bottom pressures.

Yesterday went on wreck dive to 60 fsw. My buddy was a fairly new diver who although has been certified for 12+ years had not had alot of experience in the water. His main purpose for our dives was to spearfish.

While setting up for our first dive I said that we would surface at no less than 1000psi. Of course he looked a bit bewildered at that so I explained to him the concept of Rock Bottom. It seemed he understood that.

Splash, two divers in the water with a plan. He was going to spearfish, I was going to follow him while I tested the dryness of my recently repaired drysuit.

I noticed while on the dive my buddy really wasn't keeping an eye on his SPG. I reminded him twice to check his gauge, he was still good on air. I was diving with 118 cuft of air in my tank, when I hit 1750 psi I suggested to him we start heading to the line which was close by. I had a funny feeling that he was going to be less than 1000psi. He was at 750psi and starting to freak out a bit. I signalled for him to calm down, no worries, I have a bunch of air. He shot up the line pretty fast but still semi-controlled and did his safety stop. He exited with just under 500psi in his tank.

When we got back on the boat I asked him what the deal was. He said he was afraid of running out of air. I made three points with him really quick and somewhat forcefully. First, I had a ton of air he could have used to get up, that is why we have rock bottom. Second, rising to fast is just asking to get bent. Third, he needed to check his SPG more often. He seemed to understand this concept so I decided to dive with him again.

Second dive was worse than the first one. I was having some bouyancy issues since I am new at drysuit diving. My RMV was kinda high and I knew it. He was still more interested in spearing fish than checking his gas supply. I reminded him a couple times. Finally, I said lets go back to the line. Well, we were following what I thought was the correct wreck line laid by the DM but we were not, ended up with a dead end. He started freakin out about his air supply and I was not sure where the ascent line was, although close...he was down to less than 500psi at this point. I told him to stop. I was going to hook my reel up to the wreck so we wouldnt have to do a free ascent in Virginia Beach open water and I could share air with him if he needed it. Of course Mr. Murphy wanted to have at it with me and started to shoot my bouyance all to pieces while I an getting this reel secured. I look at my SPG upon completing the reel securement, I am at 1000psi. I look up...no buddy...crap. Thinking he may have run out of air I run a 25 ft circle around my location to search for him which took about a minute then I started my ascent. I figure at this point I have to buddy to share air with so I am good. During my ascent and safety stop I am constantly looking around for him. Nada.
I surface with 500 psi in my tank and ask him what happened. He explains that he was running low on air and didnt know what I was doing so he surfaced on his own. He had trouble keeping his safety stop so held it for only a minute and popped the surface. Again I explained to him the last thing he should have done was leave the me in case he ran out of air and had to share. I also explained what I was setting up the reel for.

My lessons from this is, I need to pay more attention to my buddies SPG when I am diving. Second, the reel ascent should have been added into our diveplan. I assumed that since he owns a reel he would have known to do that. Third, maybe just maybe I should not have dove again with him after the first dive.

So what is your take on this whole incident? I have tough skin so bring it on think like chocolate syrup.

Thanks

 

[Steve50]

why plan to be at the surface with 1,000 psi ?... a little beyond rock bottom...

 

[Peter Guy]

The idea of having Minimum Air Reserves is, as you know, to make sure you and your buddy can make it to the surface safely -- and is predicated on the idea that you, your buddy and your air supply will surface with no reserves left. (Of course you can modify this, but the basic concept is that you take the last air out of the tank as you get to that Big Tank In The Sky.) There is no need to surface with a lot of air -- it is only good for keeping water out of the tank! (OK, an overstatement but I hope you get the idea.)

My one thought is not that you need to check your buddy's SPG more frequently but, to the contrary, find a buddy who is more reliable!

 

[DA Aquamaster]

"Rock" bottom is just that - a minimum. In this case planning for a bit more made sense - new drysuit, innattentive hoover buddy, delay on the bottom getting an ascent line set, etc. If the buddy had stayed there and went OOA, the OP would not have had 500 psi left at the end of the dive and would have had very close to zero anyway.

----

Don't dive with that guy again. Ever. Making a one time neveer to be repeated mistake is one thing, making a habit of making the same mistakes is something else entirely.

At a minimum, that guy needs to hang up the gun until he improves his skills, his confidence underwater and his situaional awareness.

 

[traumadiver]

I got to the 1000psi rock bottom on the premise of our dive depth. We were diving to 60 ft. He had an AL80 and I had 118cu ft on my back. After looking at 1 minute to cure the problem at depth while OOA buddy breathing @ 2.0 cuft/min, our ascent to the surface time and our safety stop I came up with 1000 psi in his tank to surface. My rock bottom would have been slightly less but I still said 1000 psi in my tank as well because I feel its better to me more conservative. Sure, I would have had alot of air in my tank, as some would call it wasted, but its better than the alternative.

 

[farsidefan1]

I'm with the "Don't dive with this guy again" crowd.

 

[ligersandtions]

I don't think diving with him a second time was bad on your part, especially since it seemed like he took to heart what you had told him about rock bottom, controlled ascents, and monitoring his gas supply....however, diving with him a third time, when he blatantly ignored all your pointers the second time, would be a mistake.

Good on you for reading and understanding the concept of rock bottom. It's not a particularly difficult concept, but it can be hard to get another buddy (who doesn't know what it is) to start ascending when they still have 1000+ psi in their tank.

Now you just need to find some good buddies to dive with! It sounds like you're on your way to being a very good diver and buddy....now just to find someone who will do the same for you.

 

[DRsharky]

I went for a dive with a guy who was a diver with excellent diving skills, BUT ignored all safety while diving. I told him what we will do, max dept I was willing to go with him and minimum air. He understood and agreed with all. But during the dive he went deeper then agreed, he never checked his air and he didn't feel like ending the dive when I told him.
At this point I decided, that it's my life, I want to keep on diving many more years and he is not worth risking my life. I went slowly up, did my safety stop and surfaced safely. He came up shortly after me, probably did his safety stop too and ended up with the tank completely empty. That was a first and last time I went diving with him.
My suggestion - find a responsible and reliable buddy like you are.

 

[divin'dog]

Yes, do not dive with this guy anymore. He's an accident waiting to happen. I've had my share of them. Guys who think nothing of coming up with 0 psi or just dive and don't pay attention to anything else but what they're doing.

Finding a buddy that dives the way you do and follows the same safety procedures you do may take a while but when you find him, diving will be so much easier and enjoyable.

Keep doing what you're doing and you will become a good diver. And don't worry about finding a dive buddy, like minded divers attract each other.

 

[Trace Malinowski]

What you had here was a team breakdown starting from the moment you began to gear up.

If we should change one thing in the industry tomorrow that would save lives, it would be the idea of a "dive buddy." When two or more divers enter the water, they take on the responsibilities for one another's lives and safety, and they take on the serious role of being a team. Lives are at stake. SWAT teams, special operations forces teams, bobsled teams, and other teams that must work together for their lives and safety practice dilligently. Even professional sports teams and little league teams practice. TEAM in diving, has not been defined and given the respect and the sobriety it deserves. The current philosophy is to put two divers in the water together and they'll look out for one another because they are trained. This is just a "feel good" security measure and probably will make matters worse.

I teach both team diving and solo courses. I tell my solo students that the 3 ways to dive are:

1. Unified, standardized, practiced buddy team - BEST
2. Solo - you know what you are doing and are properly equipped, mentally, and physically prepared to handle things alone - ACCEPTABLE
3. Loose team - two or more loose cannons, unknowns, never practiced together - WORST

With your buddy's lack of experience, the dive may have been too aggressive for a first time jaunt. 60 feet is the maximum recommended limit for open water divers. I worked in Virginia Beach and 60 feet there is much deeper regarding the type of demands the coast places on skill. You two should have gone to Lake Rawlings and began working together and adapting to one another like a quarterback and a wide receiver working to get the plays down.

You both probably have negative opinions about the other now that the dive is over. He's probably blaming you for things and you are obviously blaming him. The problem was that you lacked communication underwater. If you could talk to one another, you could simply tell him to check his gauge, or explain why you are using a reel and upline. Without FFM com units, divers are at a disadvantage to communicate easily. This leads to frustration and is something else that team practice can overcome. Light signals and hand signals can be practiced to be easily understood and a team can learn to swim together with the teamwork of the Blue Angels with enough practice. This is so important, yet the dive industry, instructors, operators, etc., do not insist upon team practice for safety.

From your account, it sounds like a big part of your buddy's problem is a combination of lack of awareness and anxiety. He wasn't taught to be a good team member and he probably is so focused on both spearfishing and his own discomfort with diving, that he cannot be an effective and reliable team member. Your first dive together, if you had to do these again, should have been him watching you sort out your suit. Spearfishing adds a whole new element of complexity to your already handicapped "team".

For the second dive, that distraction should have been removed after your first dive. You really should have thumbed it on the boat or the moment that you felt your stress level building with your suit and your problematic buddy. Losing directional awareness can become a major problem when gas reserves are low! Now, you know from experience. Losing your buddy was just as much your fault, if not more, than his. Divers should get away from the habit of looking down when working and develop good trim and buoyancy skills to allow them to work out in front of their faces always keeping the buddy or team in view.

Yes, you're right. All contigencies, such as the reel and what you will do if you can't find the anchor line, must go into the dive plan. Most importantly ... never assume!

That's just a little syrup. I'll let you off wit the light syrup this time.