Limits: what they are, why they are important and how to establish them

[The Chairman]

his way bad advice is easily identified and corrected--hopefully with polite respect.

Great point and worth repeating.

It all comes down to the reasons we are on Scubaboard. I believe that most of us are here to learn something, and second to repay the favor where we can.

Great point and also worth repeating.

The practice was changed by nearly every agency in the world after a (UHMS Undersea & Hyperbaric Medicine Society) study showed that drownings initiated by inhaling water during CESA was the number one cause of fatalities during instruction.

Which is why I teach for an agency which does not allow OW CESAs to be done. It was bad for the student back then, but it's terrible for the instructor now. All those bounce dives and ascents take their toll no matter how many want to deny it and I was about to stop teaching OW when I found one agency that didn't require it. Now, I think that there are two: NASE and IANTD.

 

[Akimbo]

There is absolutely no benefit to the diver to ascend with the regulator out of the mouth. That practice was done decades ago so the instructor could clearly see that the student was not inhaling, not because it was the right thing to do during a CESA.

Maybe, sometimes, but not a valid universal statement. A guy on my dive team was transferred from instructor duty at the submarine escape facility at New London. He helped me find find my "sweet spot" -- a simple position that makes it nearly impossible to close my airway, yet still keep water out of my mouth. Holding a second stage in my mouth interferes with holding that position, for me anyway. Besides, once the fine points of not over-exhaling are mastered, there was no need for more air from the regulator.

I totally understand why proper free ascents are no longer taught in recreational Scuba classes.

• It is very dangerous if the student screws up
• It is EXTREMELY labor intensive to teach safely and effectively
• It is difficult to teach instructors how to monitor and prevent accidental embolism -- it's not just looking for bubbles
• It requires well trained and highly motivated students
• It requires a lot of repetition, starting shallow and working deeper than most OW students are trained for
• It makes dive computers go insane

I consider mastering free ascents my most important diving skill. It is the only skill I practice on a regular basis, which is annually. It isn't about not having to carry a bailout, it's about the confidence that I can make it to the surface even when everything goes bad.

 

[The Chairman]

It isn't about not having to carry a bailout, it's about the confidence that I can make it to the surface even when everything goes bad.

When I first started diving back in 1969, SPGs were available, but like wetsuits: only for the rich. Instead, we relied on J-Valves. The first pucker (when you couldn't suck air) was always fun. and you reached down and tugged on the rod by your left butt cheek. Unfortunately, sometimes the valve had already been pushed and we realized this at the second pucker when there was absolutely positively no phreakin' air in that tank. You could continue to waste time pulling on that rod to see if it was stuck or something, but it was best to imitate a Polaris missile and head to the surface ASAP. No, sooner than that. We didn't get to choose when this happened, but the fickle flying finger of fate picked those times when we least expected or needed it. No BC back then, so when you hit the surface you couldn't just inflate and lazily bob a minute or two on the surface. You kept kicking until you got into shore. I never did a CESA in my class (it wasn't through an agency). We were expected to exercise good common sense and kick to the surface like our lives depended on it when we were OOA. I don't remember trying to breathe on the reg on the way up, though I'm pretty sure it was in my mouth the whole time until I got to the sweetest tasting air in all the world. I do remember spitting it out like it was poison when I broke the surface so I could fill my lungs with life. Those were the days and I'm glad they're done. I teach CESAs horizontally. It's a New York move: if you can do them there, you can do them anywhere!

 

[Bob DBF]

...many readers learned instead how important it is to practice the CESA without a regulator, the way it was done decades ago in the golden age of scuba instruction.

I started diving in '62 and certified OW in '80, the only time I did a CESA without a reg in my mouth was in a submarine escape tank, regs weren't allowed and I wasent there to get scuba certified. I guess my scuba training was lacking or just realistic.

You had the answer, it was not necessarily required, just easier for the instructor.


Bob

 

[Coztick]

I assume Coztick's use of the word "destroy" was simple hyperbole, and if it is, I believe it is both accurate and positive. While Pete is right that people who give bad advice should not be "destroyed" through personal attack, bad advice should certainly be corrected. I concur that this does happen regularly on ScubaBoard, and it is one of the reasons I enjoy the site.

Thanks for both catching and expanding on the intent.

I was referring to the destruction of the bad or dangerous advice. The structure and monitoring here generally promotes a positive learning experience but downright attacks poor or dangerous advice with logical and factual dabate from industry experts.

While I have witnessed the odd "spirited difference of opinion", discussion is almost always positive, progressive and tolerant if not polite.

If you think SB is harsh you should trying breathing seawater...

I'm still not sure that I would dive with any of you!

Sarcastically, Kevin

 

[Edward3c]

When I first started diving back in 1969, SPGs were available, but like wetsuits: only for the rich. Instead, we relied on J-Valves. The first pucker (when you couldn't suck air) was always fun. and you reached down and tugged on the rod by your left butt cheek. Unfortunately, sometimes the valve had already been pushed and we realized this at the second pucker when there was absolutely positively no phreakin' air in that tank. You could continue to waste time pulling on that rod to see if it was stuck or something, but it was best to imitate a Polaris missile and head to the surface ASAP. No, sooner than that. We didn't get to choose when this happened, but the fickle flying finger of fate picked those times when we least expected or needed it. No BC back then, so when you hit the surface you couldn't just inflate and lazily bob a minute or two on the surface. You kept kicking until you got into shore. I never did a CESA in my class (it wasn't through an agency). We were expected to exercise good common sense and kick to the surface like our lives depended on it when we were OOA. I don't remember trying to breathe on the reg on the way up, though I'm pretty sure it was in my mouth the whole time until I got to the sweetest tasting air in all the world. I do remember spitting it out like it was poison when I broke the surface so I could fill my lungs with life. Those were the days and I'm glad they're done. I teach CESAs horizontally. It's a New York move: if you can do them there, you can do them anywhere!

In the mid 70s we did have a SPG, but no BC. The policy at the time was to call the dive at 30bar, quite interesting if still at 30m+. Those days are gone and good riddance to them to. As for free ascents, we were told about them in the classroom, but never allowed to practise as they were considered too dangerous.

When I moved to Scotland 15 years ago the local club was still teaching the 1970s syllabus (ScotSAC continued to teach Buddy Breathing until around 2010). They didn’t want me to join as I would introduce new ideas, like using an alternative reg in OOA situations. The club no longer exists.

 

[The Chairman]

If you think SB is harsh you should trying breathing seawater...

That was funny. Thanks.

 

[The Chairman]

We didn't get to choose when this happened, but the fickle flying finger of fate picked those times when we least expected or needed it.

As a caveat: since I started using an SPG, I have never, ever without any exception run out of air. That's not luck, but good planning and monitoring. I've shared my air to others, but have never had to ask for any unless for training purposes.

 

[Neilwood]

I think it is important for all divers to continually assess themselves and their diving.

Predive - should I be doing this dive? Are my skills sufficient? Is it in my comfort zone? Is my equipment in good order?
During the dive - am I getting stressed? Is the dive getting away from me (depth, vis, buddy issues etc)?
Post dive - could I have done anything better on that dive? Was I a good buddy? Was I confident of my gas state at all times? Would I be better with more training?

There should always be something to improve on - you should never stop learning.

 

[Edward3c]

Only last Saturday I adjusted the dive plan. when doing the buddy check before diving with a new buddy, they informed me it was the first time they had dived with their own dry-suit. Instead of 18m I kept us much shallower, with a buoyancy check in 2.5m at the end. Next dive I removed 1Kg (which I carried), when we dive again I'll remove another Kg from them. Its unfortunate their instructor overweighted them in the first place. Now I have to convince them they didn't need all the lead they are carrying, by proving they can stay down with a near empty tank in 3m or less.