Solo Ascent

[MauiScubaSteve]

Divers are supposed to dive within their training and abilities. If you can't survive quadruple failur while alone at 15' (OOA, punctured BCD, mask flood & fin loss, or maybe calf cramp), is solo ascent within your training and ability?

Oh come on. What are the odds? Have you EVER had a quadruple failure? None of us should be OOA at 15' anyway. I plan my gas better than that.

LOL. Which world do you dive in? Or was that post a superb example of irony that I missed?

Does your spg or any part of your wireless integrated ever suffer hard impact (ie. checked bags or busting big chop back to dock)? OOA is not always about gas planning. Have you ever been in the water with a 300lb playful dolphin, monk seal or sea lion? They all have sharp teeth and a wild unpredictable side. I'm not saying I ever expect to be in quad failur mode, but I am confident that I could survive even all 5 in my scenario, as long as the big playful animal lets go of me.

 

[Mr Carcharodon]

If you mean to share air and continue with the dive then I think you have misunderstood the reasons for sharing air in the first place.

If you are sharing air then it's time you went up.

Why? I think you are assuming one diver is below a minimum gas reserve. Assuming either diver is above min gas why not share gas and extend the dive? It is a safe way to make the dive better for everyone and maintains the team with its benifits.

 

[SNorman]

Why? I think you are assuming one diver is below a minimum gas reserve. Assuming either diver is above min gas why not share gas and extend the dive? It is a safe way to make the dive better for everyone and maintains the team with its benifits.

You do need to keep in mind that:

1) "Min gas" is now double what it would be for one single person if diver #1 doesn't leave a minimum amount in their tank, and

2) If the diver donating air has a problem and runs out of air (regulator problem, SPG was wrong and not as much air was in the tank as expected, etc. etc.) now there is no redundancy (oh noes! now the "minimum amount" in diver 1's tank is not enough).

I think if this is done for balancing purposes it should be done early in the dive.

 

[MauiScubaSteve]

I think if this is done for balancing purposes it should be done early in the dive.

Pretty much every dive is a different situation, so how could one rule cover all situations?:no

I regularly guide a scooter dive that visits a teeth cleaning station on the return leg. I brief that we need a minimum 700psi for a proper return from the shrimp. Some dives the guests do not have the SAC for that or the scooters are not as lively as neccessary for that, so I do not stop at the shrimp, even though we could have and followed the plan. Other dives, SAC rates and scooter liveliness being sufficient, I have shared air with the guest(s) not getting teeth cleaned so everyone has enough air for a proper ascent/return to shore. Only near the end of the dive do we really know who and how much to balance.

Depending on the dive and the divers, sharing air with low diver at proper ascent/return pressure is a viable option. I have led numerous dives with fairly inexperienced divers where I have shared with a guest in order to return to the planned ascent or with the planned ending psi. In most of these instances we could have just aborted and ascended now, but instead we practiced skills that may be needed in the future. Calm clear shallow tropical conditions are a great place to practice and every diver involved in these events has enjoyed and profited from the experience.

If you are not learning and practicing every day, you are not living!

 

[Mr Carcharodon]

You do need to keep in mind that:

1) "Min gas" is now double what it would be for one single person if diver #1 doesn't leave a minimum amount in their tank, and

2) If the diver donating air has a problem and runs out of air (regulator problem, SPG was wrong and not as much air was in the tank as expected, etc. etc.) now there is no redundancy (oh noes! now the "minimum amount" in diver 1's tank is not enough).

I think if this is done for balancing purposes it should be done early in the dive.

Yes "min gas" is enough for both divers to get to the surface from a single scuba unit. It is not a universally used term admittedly, but that is way it is defined. Until recently the terminology was "rock bottom" instead of min gas. There have been quite a few previous posts on rock bottom on ScubaBoard. The change in terminology may have been a point of confusion.

You would only air share if both divers are above min gas. The risk is no different than any other dive. If diver A is at min gas, and diver B is at min gas plus some useable gas then both divers A and B can breathe down divers B’s gas to min gas. At that point if either diver A, or diver B, have a complete equipment failure they have just enough gas for both of them to get home. Plus they have had a longer dive.

 

[getwet2]

You would only air share if both divers are above min gas............ If diver A is at min gas, and diver B is at min gas plus some useable gas then both divers A and B can breathe down divers B’s gas to min gas. At that point if either diver A, or diver B, have a complete equipment failure they have just enough gas for both of them to get home. Plus they have had a longer dive.

Your above statement contradicts itself, first you say both divers are above min gas and then you say A is at min gas and then B is at min gas plus some. I don't understand how diver B can be at min gas if he still has gas to share. He is either at min or he isn't. That's like saying I've got 3000psi but I'm at min gas so I'll just breath off yours.

For the sake of the extra few minutes your going to get I don't see the point, just do another dive or get a bigger tank. Next thing you know people will be sharing the same computer. (Or are you already?) There's a little thing called Murphy's Law and sooner or later it will sneek up on you and bite you right in the butt. You read about it alot in dive accident reports. It might just be that one diver goes into a deco due to previous dives or the current picks up and takes you further or makes you work harder then you expected or the diver who's tank you are breathing from forgets to check his gauge because you are both watching something really really cool.

Now I don't want to get into the whole log book debate again but if you are diligent and honest about what you write in your logs then I wonder what you put down if you share air, do you write that it was max depth 60 feet for 60 minutes on an aluminum 80 or do you write max depth 60 feet for 25 minutes on an aluminum 80. If it's the first then you are fooling yourself and the next dive op that takes you and your log book at face value and takes you on a dive that you say you can do but really can't. As we all know, not all dive ops are the same, some will pay more attention to you then others. So if you are comfortable sharing air with an air hog then it's your choice.

Remember that Murphy is on every dive with you and he hides in your gear bag.

As for going up alone, we all know people do it all the time but you have to be confident and comfortable doing it or you shouldn't do it until you are. Every dive site is different and conditions can change quickly, you have to take all this into account as well as your experience. Diving is a risky sport so just do what ever you can to minimize the risks to yourself and your buddy, if that means always going up together then so be it. Bad things happen all the time and most of the time we don't even see it coming, even to experienced people.

Just my $0.02, that would be Canadian $

 

[jponline77]

This seems common in my travels to Mexico. It happened all the time. I was diving with my wife and she hit the 700psi threshold required for ascent. I had 1100 psi left. It seemed that both she and the dive master were happy to her to go by herself but I decided that I didn't think that was such a good idea. We were at about 60ft when we started the ascend and by about 40ft I noticed that something was wrong. Her ascent rate was too quick. Luckily I had air left in my tank and I was a few pounds overweight so that I could empty my BC and slow down. I had to hold her down at her safety stop.

She was new to her BC and I think that she had some air trapped in the BC and couldn't release it. Anyway, if I hadn't gone up with her she probably would have surfaced pretty quickly without a safety stop. Never a good practice. So, I'm pretty glad I stuck to my gut and stayed with her. There wasn't really any doubt.