CESA from 40ft

[Mr Carcharodon]

The risk to your health of doing a CESA from 40 fsw isn’t much different than doing it from 20 fsw since the most common adverse outcome is gas embolism. Of course that is mitigated by maintaining an open airway. Beyond that drowning is a very real risk if you are out of gas. CESA should be about your last strategy to resolve being out of gas. Doing regular air sharing drills and being a good buddy with your daughter should be top of the list.

DCS, especially for a dive that has a maximum depth of 40 feet is a very small risk. If you spent the whole time at 40 fsw the limit would be 140 minutes which would be hard to do without doubles or repetitive dives back to back without a reasonable surface interval. Somehow people walk away from dive training very worried about DCS. Assuming you pay attention to your training your primary focus should be elsewhere.

 

[DevonDiver]

I'd recommend simply working on your normal ascent procedure - after all, the only real difference between a normal ascent and a CESA is that you will exhale continually if OOA. All other aspects of the ascent - speed, timing etc, should be identical.

Concentrate on perfecting a direct ascent from 40' to get that speed and timing to an instinctive level. If the time ever comes that you are OOA (with no buddy), then you will have a solid foundation for the CESA.

Practice continual exhalation horizontally on the bottom portion of your dive. You can do this whenever you like.

Two things that you can and should rehearse is oral inflation at the surface and ditching weights. When you read accident reports (DAN and BSAC annual reports) you will quickly see a trend where divers do successfully reach the surface, before subsequently sinking back underwater to their deaths, because of a failure to achieve immediate positive buoyancy. Try and make these reactions instinctive. They have to be - if they are to be reliable under highly stressed emergency circumstances.

 

[Ghanguss]

I found confidence building exercises like:
1. swimming underwater in a lap pool to gauge your potential range (full breath and empty breath)
2. Breath holding exerices like static apnea programs on my pc
3. snorkelling, freediving

all give you a feel for your non breathing capability underwater.
Once you know your limitations you can adapt your diving to suit your comform level.

A local dive shop is running freediving classes where the gaol of the class is to get you to freedive to 20m / 60 ft. I think its a good way to build confidence for diving.

 

[Sinbad Scuba]

First comment: if you are her buddy and you stay close, you should never need to do a CESA. One of the pieces of equipment that has made diving safe is the DIVE BUDDY!! So, be a good buddy and stay close. Make sure you check each other's gauges. In all probability, you will use more are than she does, so she should be checking YOUR gauges.
Second comment: purchase your own regulator sets. You can probably buy a descent reg set (reg, octo, SPG) for less than $1,000 dollars. When you buy the SPG, I recommend you purchase a nav unit. It has the depth gauge and compass on the same side with tank pressure on the back side. Buy it from a local dive shop that will service your equipment annually.
With a good buddy and a good reg set/octo, neither you or your daughter should ever have to do a CESA. Feel free to practice, but you might also practice your Alternate Air Source Ascents.

 

[Rick Murchison]

... in general, when someone does a CESA from 40 feet, how much risk to your health is there from that?

There are two questions in one here.
From a purely dive-physics perspective, so long as the dive being terminated is within the normal no-stop parameters of the tables/computer, the risk of problems from a properly performed CESA is all but non-existent, though a bit greater than a standard ascent. Remember, we dove the 60/60/60 tables for decades (60 feet for 60 minutes with a 60 fpm ascent rate and no safety stop) without significant problems (in fact, nobody among the divers I knew personally ever had a DCS hit using those tables).
The second question, though, bears a little more thought. That question is "why are you doing a CESA in the first place?" The only circumstance I can think of on an adequately planned and executed dive would be an injury that requires immediate surface support - to stop life-threatening bleeding, for example - and in that case breathing and keeping the airway open shouldn't be a problem, eh?
CESA avoidance is in planning and dive protocols that remove its necessity.
To borrow and adapt an old Naval Aviation saying to diving, "The superior diver is one who uses his superior judgment to avoid having to use his superior skill."
--
You allude to a third question, if your daughter is still a child.

... if you want to dive with youngsters, there is a basic philosophy that should be followed when dealing with children that goes something like this:
You are the adult and the child is a child. A child is *not* a dive buddy, a child is a child.
Some children can learn to dive safely with proper supervision, but a child doesn't have the under-pressure decision-making capacity, to say nothing of physical strength (usually) to handle an adult with an emergency, especially if there's a modicum of "adult panic" thrown into the problem. (yes, there are many adults who're not competent buddies either, but that's another discussion entirely)
If you want a buddy, you must take someone with you to be that buddy in addition to the child.
If you take a child by yourself, you are not only diving solo with an extra burden of responsibility (the child), you are also, because the child cannot be a buddy, saddling that child with a burden he/she cannot bear. This is a bad idea. Don't do it.
If your child's other parent isn't a competent dive buddy and you don't have a trusted dive buddy willing and able to assume the extra responsibility of having your child along, hire a pro to go with you.
I don't say "don't let X yr old children dive," but I do say "don't take a child diving without a competent, enthusiastic buddy." And with very tight limits on depth, time, current, min vis, temp, etc., etc.
Rick

Lastly, if you haven't already done so, I highly recommend you take the SSI Stress & Rescue (or equivalent with your agency of choice) course.

Rick

 

[Moerby]

Thanks everybody for your comments. I think my nerves will probably settle once we've done a few dives to 40 ft and practiced these procedures. I'm probably a little too paranoid ... the result of spending too much time in the "Accidents" forum, no doubt!

 

[Easdem]

Don’t spend so much time worrying about a CESA and spend more time worrying about proper dive planning. Barring a catastrophic gear failure with buddy separation, there are very few other situations where proper dive planning and gas management can’t eliminate the need to do a CESA to end a dive. Its like worrying about what you would do if you stopped on the train tracks, your car wouldn’t start and the train was coming through. Instead, just don’t stop on train tracks…your energy can be spent on more productive things that will make you a better diver. Like BOUYANCY, slow ascents, holding proper safety stops, proper fining techniques, and NAVIGATION.

The decision to do a CESA in the real world is quite easy... It sort of goes like this: Crap. I am out of air. Where is my buddy? I don’t know. OK either I die here or swim up. Lets swim up. In any case, I would rather be bent than dead.

 

[TSandM]

I'm going to write the same thing that has been said before, but perhaps angle it a little differently . . . you are worried about doing a CESA. The only time one does a CESA is when two conditions have been fulfilled: One is completely out of gas, and nobody is available from whom to get an alternate air source. In the world where I dive, this would be considered two major failures. We plan for one.

So, how do you keep your dive within parameters that pretty much rule out two major failures? First of all, you plan your dive. You match the gas supply you have to the depth and time you are proposing (HERE is an article on doing that) and you plan gas reserves which will allow either of you to get the other one to the surface, in the event of a catastrophic gas loss. Second, you monitor your air supply in a responsible fashion DURING the dive. You don't say how old your daughter is, but if you are worried about her ability to do this, you might even think about investing in one of the wireless transmitter computers that allow you to monitor her gas. Another strategy is to ASK her at regular intervals what her pressure is, so that both of you are thinking about it.

Third, you practice air-sharing ascents, so that you are both comfortable and confident in executing them under good control. This isn't really very hard, if you spend the time to get good at it, but like all skills, it will atrophy if it is not used, and should be refreshed regularly.

And finally, you develop good diving habits that keep you close together and in communication (HERE's another article about that, from the same source).

If you have done the above, then about the only way someone is going to end up underwater with no breathing supply is a catastrophic leak or a dip tube blockage, both of which are very rare (unless you're ice diving). And in that extreme circumstance, the affected diver will have a calm, reliable buddy with plenty of gas to get both of them home without ever having to consider a CESA.

There's a reason it's way down the list of options you were taught. It's because there are easily provided, far better ones.

 

[dumpsterDiver]

I'm going to write the same thing that has been said before, but perhaps angle it a little differently . . . you are worried about doing a CESA. The only time one does a CESA is when two conditions have been fulfilled: One is completely out of gas, and nobody is available from whom to get an alternate air source. In the world where I dive, this would be considered two major failures. We plan for one.

So, how do you keep your dive within parameters that pretty much rule out two major failures? First of all, you plan your dive. You match the gas supply you have to the depth and time you are proposing (HERE is an article on doing that) and you plan gas reserves which will allow either of you to get the other one to the surface, in the event of a catastrophic gas loss. Second, you monitor your air supply in a responsible fashion DURING the dive. You don't say how old your daughter is, but if you are worried about her ability to do this, you might even think about investing in one of the wireless transmitter computers that allow you to monitor her gas. Another strategy is to ASK her at regular intervals what her pressure is, so that both of you are thinking about it.

Third, you practice air-sharing ascents, so that you are both comfortable and confident in executing them under good control. This isn't really very hard, if you spend the time to get good at it, but like all skills, it will atrophy if it is not used, and should be refreshed regularly.

And finally, you develop good diving habits that keep you close together and in communication (HERE's another article about that, from the same source).

If you have done the above, then about the only way someone is going to end up underwater with no breathing supply is a catastrophic leak or a dip tube blockage, both of which are very rare (unless you're ice diving). And in that extreme circumstance, the affected diver will have a calm, reliable buddy with plenty of gas to get both of them home without ever having to consider a CESA.

There's a reason it's way down the list of options you were taught. It's because there are easily provided, far better ones.

Recommending a remote monitoring of gas supply by the dad removes responsibility from the child. If they are new divers they need to get used to frequently checking each others air supply. Why recommend some complex and expensive (electronic) solution to a problem that can be addressed easily by more frequently monitoring of each person's air supply?

If the guy is really worried about making it to the surface from a shallow dive, I would rather spend my money on a 6 cu-ft pony bottle and a cheap reg, rather than an expensive electronic remote gas pressure monitoring system.

 

[matt_w]

Thanks everybody for your comments. I think my nerves will probably settle once we've done a few dives to 40 ft and practiced these procedures. I'm probably a little too paranoid ... the result of spending too much time in the "Accidents" forum, no doubt!

I understand your anxiety, I had been diving 20 years when my Kids were certified at 10 and 13. Recent accidents discussed here would certainly add to that. I still watch my kids closely (now 13 and 17) but the anxiety fades. Instead of worrying about CESA, I would recommend staying together and routinely checking each others air. Remember to ascend with a healthy reserve.

The skills I prefer to practice are regulator recovery and mask remove and replace. These are common occurrences and if the skills are not well rehearsed, they can lead to accidents. Occasional air Sharing exercises are ok too. I would only practice CESA if you are very good at contolling your own ascent rate and understand how to monitor you ascent.

Good buddy checks and good air managent are the best ways to stay safe.

I have also learned the more relaxed I am, the more comfortable my kids are. Safety is very important, but we need to have fun too.

Be safe, have fun,

Matt