Low on air done right?

[Phishie]

Wearing different sized tanks was the first error.

I _am_ a novice. I'm having trouble seeing how this is an error. If people have different sized tanks, I don't see why it should be considered a necessity to go out and buy a new tank just to dive with someone else. It should be considered in the dive plan yes, but a whole new tank? I'm not understanding why.

 

[nereas]

You also need to take into consideration how fast you and they are moving. New divers often have inefficient kicks that help them burn through their air and they tend to try to go fast which makes it worse. I do a lot of pausing with the newer divers to encourage them to slow down and see what's around them. Slower also gives them a chance to work on their buoyancy control instead of using kicking to maintain their position in the water.

I know one diver who will literally swim circles around his buddy when they are going slow, he likes going fast and feeling like he's "getting somewhere". Make sure that isn't you when you're diving with new divers

New divers are fun to dive with but you do have to make some adjustments when first incorporating them into your stable of buddies. It's as much a learning experience for you as it is for them and diving is all about learning.
Ber :lilbunny:

Precisely right.

Whenever someone takes on a newer diver as their buddy, his/her life is in your hands.

You would not feel too good about being responsible for their death.

And all your friends would never ever let you forget it.

 

[nereas]

I _am_ a novice. I'm having trouble seeing how this is an error. If people have different sized tanks, I don't see why it should be considered a necessity to go out and buy a new tank just to dive with someone else. It should be considered in the dive plan yes, but a whole new tank? I'm not understanding why.

It's just a clue, Phishie.

If you and I are about the same size, and the same gender, and our tanks are the same size, then we are going to use up about the same amount of air/nitrox at about the same rate.

If someone is wearing a bigger tank than you, and they are more experienced than you, and they therefore breathe less than you, this is a clue from the start that you are going to be OOA on this dive, unless you both pay very special attention.

Just a clue.

The ocean and oceanside are always full of clues. Clues as to whether this is a good day to dive, or not. It helps to be sensitive to these clues. Crashing breaking waves are a clue. A big dorsal fin at the end of the surf zone is a clue. And a bigger tank on your buddy/buddies is a major red flag.

Welcome to Scubaboard and the Internet, Phishie. It is a great place to learn things, before you go out diving. And a good place to find some bargains on gear.

I got a great, almost new $1000 helium dive computer here for $500 from a great diver in Florida who just didn't like it. Now it (the computer) has a home, and its happy, and I am happy, and I take it out on every dive, helium or nitrox or air.

 

[jjhill]

I too get annoyed, particularly when I see novices making huge mistakes that endanger even newer novices.

The errors on this dive began during the planning stages, before going into the water.

Wearing different sized tanks was the first error.

Having a 3-man CF was the second.

Not paying close attention to the 3rd novice was the third.

Not proceeding to the safety stop immediately was the fourth.

Four failures. It's quite lucky that no one drowned on this dive.

Half of all scuba fatalities are by novices.

Nice try at a rhetorical reply, JHill. Not one that was very seasoned or logical however. I am sure you will get better at failure analysis with time, however. Everyone does, if they live long enough.

I fully agree that this dive could have gone better and that mistakes were made. My point is merely that it is unnecessary to flame diver who comes on here looking for ways to improve.

Flame me all you want, I have thick skin and a thicker wetsuit, I just don't like undermining the confidence of a new diver. Pointing out mistakes and discussion is one thing, flaming and antagonizing is another.

 

[Gombessa]

I consider this a successful failure. No one deployed a pony bottle (all contigencies are planned as if we did not have the pony tanks.)

So, some lessons learned, any thoughts?

I'd agree with you - a "successful failure." Hopefully it was a lesson for your newbie buddy too, to vigilantly keep track of his gas, and not be too embarrassed/intimidated to turn the dive or signal thumbs up when his air was low.

I would recommend making use of rock bottom in planning your dives, especially with newbies. Determine the pressure needed to return him and an OOA buddy to the surface with all safety stops (at 50ft, "air hog" newbie, let's call it 800psi on an AL80), and subtract that from total gas. If you decide to turn at halfway, that leaves you with 1100 in and 1100 out, or 2100 to turn.

Now, if you're left with that 800psi and can do a shallow 10-15fsw scuba back rather than surface-swim, it should be fine to use the extra 300psi or so at that point.

 

[Phishie]

If you and I are about the same size, and the same gender, and our tanks are the same size, then we are going to use up about the same amount of air/nitrox at about the same rate. If someone is wearing a bigger tank than you, and they are more experienced than you, and they therefore breathe less than you, this is a clue from the start that you are going to be OOA on this dive, unless you both pay very special attention.

This makes sense, and would definitely be important to pay attention to in the dive plan, but would it still be an error to even begin a dive if I'm wearing a different sized tank than my buddy? Even if the difference is planned for?

Welcome to Scubaboard and the Internet, Phishie. It is a great place to learn things, before you go out diving. And a good place to find some bargains on gear.

Thanks. Scubaboard has been useful for finding out a lot, especially forums like this one where I can learn from the mistakes of others in real world situations and the correct responses. I've been on the Internet for 15 years though, but thanks for the welcome I always prefer to learn from the mistakes of others on what to do before an emergency happens rather than afterwards.

 

[nereas]

...Flame me all you want, I have thick skin ...

I did. I pointed out that your rhetoric was logically unsound. You took it well.

 

[Kevin Carlisle]

Has it occured to anyone that what works for one does not work for everyone. I think all on here have some good points. I think he did good to bring this on here for discussion so he could LEARN from it. The larger tank should mean nothing, I dive all the time with people with different tank sizes. By RULE in any tech class, the air hog gets the smaller tank for air management and gas planning. I just did a 105 ft dive in the gulf, spent 22 minutes at 105 to 102 ft. At my NDL limit I worked my way up to the boat and after 44 minutes total I still had 1/3 of an AL80. Planning will be different with each diver and thats where I think he made the mistake. If your not relaxed you air consumption rate will be gone and there ae many factors that will come into play there as you all know. I posted in this one earlier and mentioned the 1/3- 2/3 rule. But really that will not matter if the person diving does not monitor their gas supply.

 

[nereas]

This makes sense, and would definitely be important to pay attention to in the dive plan, but would it still be an error to even begin a dive if I'm wearing a different sized tank than my buddy? Even if the difference is planned for?
...

You have got to know your own limitations, Phishie.

It is better to have a plan that automatically takes care of these limitations, rather than a plan that requires a lot of special procedures. The acronym for this is KISS.

It is also better to be diving with a person of same skill set as yourself, rather than have a major disparity. Beginner with intermediate is the worst combination.

Beginners ideally dive with other beginners, or else with instructors or divemasters.

Intermediate divers best dive with each other.

Tanks of the same size place the same time constraints on everyone, and then you do not need to make any special considerations.

 

[24940]

That would depend on what happens @ 1500. If they start the ascent, or move with the current instead of against it, it's probably OK.

Anything else just means it's a plan to have 0 PSI remaining when they reach the exit.

Terry

He wrote "turn the dive", not "end the dive", so I'd say his planning of getting back to the boat with 0psi is rather flawed.

His statement on mismatched tank capacities is equally flawed. Take two divers with the same tanks, but very different SCR as an example of why that logic is flawed.

Gas planning should be based on the weakest link. That might be the person with the smallest tank capacity or it might be the guy with the highest SCR. By the time I get students to OW, I know who breathed how much and base the plan on their SCR. I typically do two dives on a single tank and finish up with 800+psi, while they are using one tank per dive and coming back with a minimum of 800psi. I'm diving a steel 100 and they are using AL80.... I've never had a student come back with less than 800psi, because that's how we plan it.