"Correct Weighting" Identified as #1 Needed Improvement in SCUBA Diving

[stuartv]

This conversation has been hashed and rehashed here about 15,391 times.

The current OW training process offered by most agencies (at least, in the U.S.) turns out people who are, well, really about as competent for diving as most 16 year olds are to drive when they get their very first driver's license. Or maybe even not that good.

But, the statistics seem to make a pretty reasonable case that even with that low level of competence among new divers, they are by-and-large able to get out and dive without getting hurt. As much as some people would like to raise the bar on minimum skill level in order to get an OW card, it really seems as though there is not strong statistical support to raise that bar on the basis of making people safer. The DAN report said there were an estimated 3,000,000 scuba diving participants in the U.S. in 2014. That's people, not dives (as I interpret the statement in the report). And there were only 54 fatalities in the U.S. in that year and 1220 scuba-related emergency room visits.

So, as low as the OW bar is, it still seems to be producing divers that are pretty safe. And if that bar can be that low (i.e. that inexpensive is what it really comes down to) while still being safe, that seems like a good thing. The lower the barrier to entry, the more people can at least try scuba.

The actual report is here:

https://www.diversalertnetwork.org/medical/report/AnnualDivingReport-2016Edition.pdf

 

[Remy B.]

Yes that is what I mean there is no other way around it.

 

[TMHeimer]

A also agree. Besides, if you start extending the course time, adding PPB, maybe my pet peeve Rescue skills--then must raise instructor/DM pay (God forbid), it will cost the student more for the course and be a deterrent.

 

[REVAN]

Again, I'll suggest basic OW scuba should be taught without a BC. Less equipment, fewer things to teach, less time involved, but the core weighting skills will actually be learned by the student or they won't be able to conduct a successful dive to pass the class.

The BCD is specialty equipment, in much the same domain as a dry suit. OW students graduate knowing what a dry suit is, but without having to use one to get OW certified. Would a training agency push a student to learn to dive a dry suit without first covering the basics of weighting skills? Absolutely not! So, why do they do this with BCDs?

Training agencies/ instructors should start treating the BDC as the specialty device they are and not use them as a method to gloss over core diving skills. Everything else will fall into place.

 

[uncfnp]

If you read the annual report you will find case studies of divers being grossly over weighted.

The key point here that seems to be lost is "grossly over weighted." I find it hard to imagine that even the most incompetent instructor is teaching their students to be over weighted to the degree cited by DAN.

 

[boulderjohn]

After many years of teaching OW, watching others teach OW, and then experimenting with different approaches, I am quite convinced that the primary cause of overweighting is the continued teaching of OW classes to students who are on their knees while learning basic skills.

For those who don't know, a number of years ago I experimented with teaching students while neutrally buoyant and in horizontal trim rather than on their knees. I convened a number of like-minded people, and we submitted an article on this to PADI. PADI agreed to publish it in a reduced form (it was a very long article), and Karl Shreeves of PADI and I worked on the final wording. the article was published in PADI's professional journal, The Undersea Journal. After that, PADI obviously experimented on their own, for two years later they began to advocate our approach as the best way to teach. Unfortunately, they still allowed the traditional approach on the knees, and that is still what most instructors do.

Before the article was published, I was asked to pose for pictures comparing the two methodologies. I did the pictures for neutral instruction first, weighted the way i always was in pool instruction--about 6 pounds overweighted so that I can better control students in an emergency. Then I posed for the pictures while kneeling, something I had not done for years. I couldn't do it. I had to double my weight in order to stay firmly planted on my knees to the degree that I needed in order to perform the skills.

I have since watched other instructors teaching their OW classes on the knees, and I would say that in order to get the students to kneel comfortably and stably, the students must be at least 10 pounds overweighted, and it is frequently more. The students learn that that is the weight they need to dive, when it is actually only the weight they need to kneel on the bottom of a pool.

 

[boulderjohn]

I am going to go farther and say that another cause of the problem is all those ridiculous online weight calculators. I have not seen one yet that does not tell me I need at least double the weight I really need.

 

[billt4sf]

What I don't understand is those reports where the diver was very over weighted and didn't have a problem until the end of their dive.

How do you get to a safety stop being too heavy to get neutral? If you're close to the end of your dive, then you were even more negative at the start. Are they spending the whole dive finning to keep from sinking, but not recognizing that there is a problem?

I dived quite a while overweighted. I started with a lot of weight as a newbie, and just kind of kept with that. Several times I had problems keeping down on my safety stop, and so I thought the problem was that I needed more weight - WRONG!

A friend fixed it for me when we were doing a safety stop together -- he saw that instead of keeping a fixed position in the water column, I was rising too far up and too far down, alternately adding and releasing air from my BC. He took a 6-lb weight off of me, and when that wasn't enough, he took ANOTHER 6 lib weight off of me -- and let some air our of my BC. At the time, I didn't really follow why he was doing this, but I trusted him because I had dived with him and from talking with him.

DIVING BECAME SO EASY from that point onwards!

After that I learned how to do proper weight checks and now I'm down to 5 lbs (2 kg) with a 5 mil full wetsuit.

- Bill

 

[REVAN]

A friend fixed it for me when we were doing a safety stop together -- he saw that instead of keeping a fixed position in the water column, I was rising too far up and too far down, alternately adding and releasing air from my BC. He took a 6-lb weight off of me, and when that wasn't enough, he took ANOTHER 6 lib weight off of me -- and let some air our of my BC. At the time, I didn't really follow why he was doing this, but I trusted him because I had dived with him and from talking with him.

DIVING BECAME SO EASY from that point onwards!

This is because BCDs are unstable. The more air in the BC the more unstable it is. Also, the more shallow you are the worse it will be, so deco and safety stops are especially bad. If you have a lot of air in it, you will have to constantly fight its instability adding and removing air from the BCD.

Controlling your buoyancy becomes trivial if you are neutral when the BCD is empty. This is an analog for diving without a BCD.

The truth is, if a diver is proficient at diving without a BCD, they will likely be able to dive with one without problems. If they cannot dive without a BCD, they will likely struggle to dive with one for the exact reason you described above. They will likely dive with too much weight and struggle to stay ahead of the devices inherent instability, wasting air in the process and making accurate gas management more difficult (another DAN point for improvement in the previously quoted article).

 

[Remy B.]

Depending what BCD they have, is they have a wing type BDC that is stable, if they have the "El chepo" BCD like all schools have and understandable that they do, then it requires finesse and practice.