Suunto Eon Steel Skipped Safety Stop

[doctormike]

Do you think he is just swimming around chasing students making rapid ascents? Or perhaps he is accompanying his students on the mandatory Open Water CESA skill...like he indicated in his original post?

Does the fact that something is mandated by a dive agency change an instructor's decompression stress and chance of injury?

 

[stuartv]

Do you think he is just swimming around chasing students making rapid ascents? Or perhaps he is accompanying his students on the mandatory Open Water CESA skill...like he indicated in his original post?

Are you saying that PADI (or whatever agency he is teaching for) standards require the instructor to make a too-rapid ascent with each and every student that does their CESA? So, no amount of thought will allow him to come up with a way of teaching the required skill (and adhering to standards) without making a bunch of too-rapid ascents?

 

[Sevenrider860]

Does the fact that something is mandated by a dive agency change an instructor's decompression stress and chance of injury?

It does not. If the student makes a CESA at 40 feet a minute his Suunto will complain. Since he surfaces with that student he also missed the Suunto stop that does not penalize you on the next dive. So now he either gets penalized on NDL or he extends his surface interval. The more conservative NDL will not affect much unless perhaps he scheduled a deep dive after his his dive with the CESA.

Students on their first CESA don't always stay at 30 feet a minute and the Suunto squawks. Had he worn a Cobalt, Petrel or any other computer it would be a non-issue. Understanding the Suunto way of things also makes it a non-issue also.

There is an argument that doing the CESA at all contributes to decompression stress and a chance of injury...even at a 25 to 30 foot per minute ascent rate the Suunto does not complain about.


---------- Post added January 12th, 2016 at 06:36 PM ----------

Are you saying that PADI (or whatever agency he is teaching for) standards require the instructor to make a too-rapid ascent with each and every student that does their CESA? So, no amount of thought will allow him to come up with a way of teaching the required skill (and adhering to standards) without making a bunch of too-rapid ascents?

Too rapid by who's standard? Suunto's? Did you do exactly 30 feet a minute on your first CESA? If you did 35 a Suunto would not like it. You did not fail the exercise and you aren't making a too rapid ascent ( up to 60 is allowed by standards ). I teach slower is better, but we are simulating an OOA emergency, so keeping a Suunto algorithm happy by staying at 10 feet for a minute on the ascent is not happening.

The next dive has a more conservative NDL limit, that's all. After making a few CESA's following the conservative NDL on the next dive is not a bad thing.

Some said put the computer in gauge mode...why on earth would he do that? The Suunto saw his accent rate and multiple ascents as a contributor to high microbubble build up. So it makes the next dive a bit more conservative if he does not perform the Suunto "Mandatory Safety Stop." I would say that the Suunto is actually working to PREVENT decompression stress and chance of injury rather than contributing to it.

The original poster asked how his Suunto worked when performing CESAs. He wanted to know if it would lock him out. There were many that advised him that there is an expectation that he should of read the manual and understand how his computer works...and I agree with that. How the topic was turned into him being a bad instructor because he was chasing students around because they were constantly ascending too rapidly is unknown.

 

[DevonDiver]

PADI released a 'finding' on the practice of CESA a few years ago. There was a lot of concern about it - given that instructors might have up to 8 students (8 CESAs).... and not every student gets CESA right the first time, thus needs repeats..

PADI quoted a bunch of statistics that basically defended the practice of doing multiple, repetitive bounce dives (the ultimate saw-tooth disaster) a routine basis. There weren't many reported cases of DCI. I love statistics.... especially when they are used to defend corporate liability. "Move along, there's nothing to see here"....

Take an instructor who's diving all the time... slow tissues highly saturated when they wake up in the morning... they spend all their time relatively shallow, up and down and up down, then bash them through 8+ rapid ascents to the surface, then re-descend (crush and conjoin those plethora of microbubbles). Maybe they don't end up 'chamber bent'.... after all, why report that aching shoulder, that rash, that lethargy?? If you're bent, it'll mean months of missed work...it won't look good... and it might just be a salt rash...or jellyfish stings.... or maybe you hurt the shoulder carrying tanks.... and maybe you're just tired from diving every day.... blah blah blah and varied denials... A couple of beers after work and the ache will go.... and you're diving again at 8m the next morning and it doesn't hurt when you dive, right?

But PADI say it's ok..... and that's cool..... because if they didn't.... we'd (instructors) all be joining a sweet class action huh?

 

[doctormike]

Too rapid by who's standard? Suunto's?

Well of course Suunto's - if you buy a Suunto computer, the implication is that you want it to tell you when you are at increased risk for DCS and keep you from doing things that contribute to that. You may feel that Suunto is wrong, but then what's the point of buying a Suunto?

It would be as if you hired an instructor who gave you diving advice, you disagreed with that advice, and instead of finding another instructor you were upset that your instructor didn't just give you the advice that you wanted.

I teach slower is better, but we are simulating an OOA emergency, so keeping a Suunto algorithm happy by staying at 10 feet for a minute on the ascent is not happening.

When you say it's not happening, is that because you want to do multiple ascents at high speeds because that's the best way to get a class of divers through the course material, or because you are sure that this practice doesn't contribute to decompression stress in the instructor?

Some said put the computer in gauge mode...why on earth would he do that? The Suunto saw his accent rate and multiple ascents as a contributor to high microbubble build up. So it makes the next dive a bit more conservative if he does not perform the Suunto "Mandatory Safety Stop." I would say that the Suunto is actually working to PREVENT decompression stress and chance of injury rather than contributing to it.

I agree with this

The original poster asked how his Suunto worked when performing CESAs. He wanted to know if it would lock him out. There were many that advised him that there is an expectation that he should of read the manual and understand how his computer works...and I agree with that. How the topic was turned into him being a bad instructor because he was chasing students around because they were constantly ascending too rapidly is unknown.

I don't know if he is a bad instructor, but he did say that the problem was his computer's reaction to his teaching practices. And some of the other commenters felt that practice was unsafe, so it's a reasonable part of the discussion. They may be wrong or right, but it's certainly fair game for the conversation...

 

[Sevenrider860]

Well of course Suunto's - if you buy a Suunto computer, the implication is that you want it to tell you when you are at increased risk for DCS and keep you from doing things that contribute to that. You may feel that Suunto is wrong, but then what's the point of buying a Suunto?

I guess this is where you and I will have to disagree. The Suunto is simply providing an alert that because of the multiple ascents and descents and an indication of a rapid ascent it will be providing me two options to reduce risk. Hold at 10 feet for about a minute or have a more conservative NDL on the next dive. I don't feel the Suunto is wrong at all. This is as it is designed and as I fully expect it to do. That is all it is.

You instructor comparison does not apply...as I do not disagree with the Suunto assessment of increased risk in performing multiple CESAs and appreciate the more conservative NDL it provides.

 

[doctormike]

I guess this is where you and I will have to disagree. The Suunto is simply providing an alert that because of the multiple ascents and descents and an indication of a rapid ascent it will be providing me two options to reduce risk. Hold at 10 feet for about a minute or have a more conservative NDL on the next dive. I don't feel the Suunto is wrong at all. This is as it is designed and as I fully expect it to do. That is all it is.

You instructor comparison does not apply...as I do not disagree with the Suunto assessment of increased risk in performing multiple CESAs and appreciate the more conservative NDL it provides.

OK, and as an instructor I would defer to you on this, since I don't know much about teaching scuba diving. But the point is that you can't eliminate the increased decompression stress of multiple CESAs with or without ascent rate violations simply by having a more conservative NDL. Multiple ascents increase risk.

You may be willing to trade that risk for operational considerations (like teaching), but I wouldn't assume that as long as you extend your surface interval (or even stop diving that day), you are going to be OK. I found that out after my chamber ride for a spinal cord hit that I got during a single dive with multiple ascents, nowhere near NDLs.

 

[Ozensha]

Too rapid by who's standard? Suunto's? Did you do exactly 30 feet a minute on your first CESA? If you did 35 a Suunto would not like it. You did not fail the exercise and you aren't making a too rapid ascent ( up to 60 is allowed by standards ). I teach slower is better, but we are simulating an OOA emergency, so keeping a Suunto algorithm happy by staying at 10 feet for a minute on the ascent is not happening.

You hit my point exactly. I even stated in an earlier post that I never violated PADI standards and never exceeded 60ft/min. This only happened on the CESA exercise where students tend to try and move faster than something like an alternate air source ascent. So by PADI standards this was not a rapid ascent, but for Suunto’s RGBM it was. So which one is right? In reality neither is 100% correct. It all comes down to many personal factors including weight, hydration, level of exertion, history of DCS, ext. The list goes on. It all comes down to the level of risk you are willing to accept. After listening to what others had to say about long term effects of DCS I personally am now going to adjust to the Suunto NDL and ascent rate standards. I would like to keep diving into my old age.

The original poster asked how his Suunto worked when performing CESAs. He wanted to know if it would lock him out. There were many that advised him that there is an expectation that he should of read the manual and understand how his computer works...and I agree with that. How the topic was turned into him being a bad instructor because he was chasing students around because they were constantly ascending too rapidly is unknown.

All I was asking about was how 1 particular part of the computer worked because the manual was not exactly clear in my opinion on that part. I would rather ask here prior to my next dive so that I understand exactly what is going on rather than attempt to figure it out myself. There are a lot of divers on here with a lot more experience than me with this type of thing. This is only the second computer I have ever owned. I spent the first few years of diving with only an SPG and depth gauge. I relied on tables and a stop watch.

People tend to not read everything posted and like to add pieces to the story to fit their narrative. The fact is, I am NEVER chasing students around and my students are NEVER exceeding PADI standards. I honestly don’t know how staying within my agencies standards makes me a bad instructor either. I think the fact that I am asking questions and continually trying to learn new things makes me a great instructor. I am taking all of the good advice from [user]DevonDiver[/user], [user]doctormike[/user] and you [user]Sevenrider860[/user] into account and will push my students to be more conservative in the future. Like I said, I am a new instructor. I challenge anyone here to tell me that they knew as much when they first started teaching as they do now. Anyone?

In the end there are always going to be those individuals who just want to try and put others down to make themselves feel superior. I am going to just ignore them and take the advice of the people who genuinely wanted to contribute to the discussion.

 

[stuartv]

So by PADI standards this was not a rapid ascent, but for Suunto’s RGBM it was. So which one is right? In reality neither is 100% correct.

I would say that what is "right" is the ascent rate built into whatever algorithm you are choosing to dive by. If you dive by the PADI tables, then what is right is whatever ascent rate the PADI table assumes. If you dive by a computer, then whatever ascent rate that computer assumes in its deco algorithm (which it uses to calculate your NDL) is what is right.

If you use tables and the table says your NDL for your depth is 40 minutes, then if you stay at the depth for 40 minutes and ascend at whatever rate the table assumes, then you are diving by the table. If the table assumes 30 ft/min and you ascent at 60 ft/min then you are elevating your risk of DCS beyond what the table predicts to be safe.

Ditto for a computer. If the computer assumes a 30 ft/min ascent and you stay down until your NDL hits 0, and then you ascend at 60 ft/min to the surface, that means you have hit the surface with a significantly higher tissue tension gradient (against ambient pressure) than what the computer thinks is safe - because you got to the surface with half the amount of deco time that the computer wanted you to have. You realize you are decompressing as you ascend, even though you don't stop, right?

I honestly don’t know how staying within my agencies standards makes me a bad instructor either.

If my earlier post made you feel that I was suggesting you are a bad instructor, then I apologize. That was not at all my intent.

I said earlier "maybe you should rethink how you're teaching." I didn't mean any extra implications. I just literally meant, maybe you should think through again how you're teaching and see if you can figure out a way to stay within standards and still avoid all those rapid ascents. For example, can you get a couple of assistant instructors to help you during the CESA exercises and have one half way to the surface and one at the surface, so you don't have to personally accompany each student from the bottom to the surface?

I am not an instructor and don't know your standards, so I don't know if you have options or not. It just seems like any agency would have their teaching standards setup so that an instructor CAN teach all they are supposed to and do it correctly, without having to damage themselves (which is what it sounds like you are doing).

 

[Ozensha]

I said earlier "maybe you should rethink how you're teaching." I didn't mean any extra implications. I just literally meant, maybe you should think through again how you're teaching and see if you can figure out a way to stay within standards and still avoid all those rapid ascents.

Thanks for explaining and I am personally rethinking the way I am teaching. I always am. I do need to meet the standard and there are maximums listed in the PADI manual that every instructor must adhere to. One being that we cannot exceed a 60ft/min ascent rate. It doesn't say we can't go slower.

The only difficulty with this skill that no one has mentioned so far is that a CESA or Controlled Emergency Swimming Ascent is that students must perform it on a single breath. If they breath in half way up I have to take them back down to do it again. The skill must be performed at a depth of 6-9 meters/20-30 feet. At a 30ft/min ascent rate students would need to take between 40-60 seconds to surface on a single breath, exhaling the entire way up. For new divers this can be not only difficult but may also create a lot of anxiety. So if a student takes 20 seconds to surface from 20 feet then did they perform the skill correctly? Yes. If they take 40 seconds but inhale half way through did they perform the skill? No. In this case we would need to keep going down and back up until the student does it on a single breath.

As DevonDiver aluded to earlier...

There was a lot of concern about it - given that instructors might have up to 8 students (8 CESAs).... and not every student gets CESA right the first time, thus needs repeats..

What is more dangerous? 16 CESAs because everyone needed to do it twice or ascending between 30-60ft/min, which would trigger the Suunto ascent alarm.

I might start a new post to see how other instructors tackle this issue...