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

[drbill]

"Correct weighting" is certainly important, but it also depends on factors besides body weight, fat content, wetsuit thickness, etc. For example, I always "overweight" myself because I need to be stable when filming. "Correct" weight is fine for mid-water trim, but not for all cases.

Of course back in the old days before Mae Wests and later BCDs were readily available, we also determined correct weight based on dive depth.

 

[Colliam7]

It appears that this thread is going in circles. I don’t see any material disagreement regarding the importance of proper weighting in the posts in this thread. Yes, the OP says he likes to weight himself within 1lb of ideal, some others have said they are OK with being within 2-3 lbs. But, that difference isn’t a substantive issue.

As best I can tell, the argument appears to center around whether teaching divers proper weighting is possible if the diver is wearing a BCD. There would appear to be ample evidence – thousands of dives and divers do that all the time, safely and successfully – that it can be done. What is perhaps more important is training divers to learn to control their buoyancy without using their BCD to the extent possible. The OP seems to think that it cannot be done. Others, with what appears to be a considerable body of experience, think it can. My own experience certainly suggests that it can be done. Starting with Confined Water training divers are ‘encouraged’ to use their breathing (only) to make minor depth adjustments. That process continues through the Open Water dives for initial certification, and beyond. One of the exercises I have divers perform in Advanced Open Water is to pick up and discard a series of weights, while swimming a linear course – without using their BCD to adjust buoyancy. For example, 6 weights are placed on the bottom (usually atop a piece of rock) in a line, approximately 15 feet apart. Each AOW diver has to swim to the first rock, and pick up the first weight, then swim to the second rock (without touching the bottom), deposit the first weight and pick up the second weight, swim 15 feet to third rock, and deposit the second weight and pick up the third weight, etc. The first weight may be 2lb, the second weight 6lb, the third 1lb, the fourth 5lb, the fifth 3lb and the last weight 4lb. Sometimes, I add an 8 lb weight to the mix. They are not allowed to use their BCD (and I and/or my DM are watching them), and the expectation is that they will not silt out the line. Exercises like this help them learn how to manage their buoyancy with their breathing, rather than their BCD. They don't need to dive without a BCD to learn that.

Before they even do that exercise, they perform a proper weight check, which necessarily involves a fully deflated BCD.

To persist in arguing that the only way to teach divers how to properly weight themselves is to have them dive without a BCD seems silly. As several have pointed out, it is actually potentially dangerous, and unnecessarily removes a margin of safety. I don’t care to dive with such a limited margin of safety. I certainly don’t care to teach that way. A quote from the movie Deepwater Horizon comes to mind: “Running out of fuel as the plane tires touch the ground is not smart.”

 

[Joneill]

It appears that this thread is going in circles. I don’t see any material disagreement regarding the importance of proper weighting in the posts in this thread. Yes, the OP says he likes to weight himself within 1lb of ideal, some others have said they are OK with being within 2-3 lbs. But, that difference isn’t a substantive issue.

As best I can tell, the argument appears to center around whether teaching divers proper weighting is possible if the diver is wearing a BCD. There would appear to be ample evidence – thousands of dives and divers do that all the time, safely and successfully – that it can be done. What is perhaps more important is training divers to learn to control their buoyancy without using their BCD to the extent possible. The OP seems to think that it cannot be done. Others, with what appears to be a considerable body of experience, think it can. My own experience certainly suggests that it can be done. Starting with Confined Water training divers are ‘encouraged’ to use their breathing (only) to make minor depth adjustments. That process continues through the Open Water dives for initial certification, and beyond. One of the exercises I have divers perform in Advanced Open Water is to pick up and discard a series of weights, while swimming a linear course – without using their BCD to adjust buoyancy. For example, 6 weights are placed on the bottom (usually atop a piece of rock) in a line, approximately 15 feet apart. Each AOW diver has to swim to the first rock, and pick up the first weight, then swim to the second rock (without touching the bottom), deposit the first weight and pick up the second weight, swim 15 feet to third rock, and deposit the second weight and pick up the third weight, etc. The first weight may be 2lb, the second weight 6lb, the third 1lb, the fourth 5lb, the fifth 3lb and the last weight 4lb. Sometimes, I add an 8 lb weight to the mix. They are not allowed to use their BCD (and I and/or my DM are watching them), and the expectation is that they will not silt out the line. Exercises like this help them learn how to manage their buoyancy with their breathing, rather than their BCD. They don't need to dive without a BCD to learn that.

Before they even do that exercise, they perform a proper weight check, which necessarily involves a fully deflated BCD.

To persist in arguing that the only way to teach divers how to properly weight themselves is to have them dive without a BCD seems silly. As several have pointed out, it is actually potentially dangerous, and unnecessarily removes a margin of safety. I don’t care to dive with such a limited margin of safety. I certainly don’t care to teach that way. A quote from the movie Deepwater Horizon comes to mind: “Running out of fuel as the plane tires touch the ground is not smart.”

Well said!

 

[Neilwood]

It appears that this thread is going in circles. I don’t see any material disagreement regarding the importance of proper weighting in the posts in this thread. Yes, the OP says he likes to weight himself within 1lb of ideal, some others have said they are OK with being within 2-3 lbs. But, that difference isn’t a substantive issue.

As best I can tell, the argument appears to center around whether teaching divers proper weighting is possible if the diver is wearing a BCD. There would appear to be ample evidence – thousands of dives and divers do that all the time, safely and successfully – that it can be done. What is perhaps more important is training divers to learn to control their buoyancy without using their BCD to the extent possible. The OP seems to think that it cannot be done. Others, with what appears to be a considerable body of experience, think it can. My own experience certainly suggests that it can be done. Starting with Confined Water training divers are ‘encouraged’ to use their breathing (only) to make minor depth adjustments. That process continues through the Open Water dives for initial certification, and beyond. One of the exercises I have divers perform in Advanced Open Water is to pick up and discard a series of weights, while swimming a linear course – without using their BCD to adjust buoyancy. For example, 6 weights are placed on the bottom (usually atop a piece of rock) in a line, approximately 15 feet apart. Each AOW diver has to swim to the first rock, and pick up the first weight, then swim to the second rock (without touching the bottom), deposit the first weight and pick up the second weight, swim 15 feet to third rock, and deposit the second weight and pick up the third weight, etc. The first weight may be 2lb, the second weight 6lb, the third 1lb, the fourth 5lb, the fifth 3lb and the last weight 4lb. Sometimes, I add an 8 lb weight to the mix. They are not allowed to use their BCD (and I and/or my DM are watching them), and the expectation is that they will not silt out the line. Exercises like this help them learn how to manage their buoyancy with their breathing, rather than their BCD. They don't need to dive without a BCD to learn that.

Before they even do that exercise, they perform a proper weight check, which necessarily involves a fully deflated BCD.

To persist in arguing that the only way to teach divers how to properly weight themselves is to have them dive without a BCD seems silly. As several have pointed out, it is actually potentially dangerous, and unnecessarily removes a margin of safety. I don’t care to dive with such a limited margin of safety. I certainly don’t care to teach that way. A quote from the movie Deepwater Horizon comes to mind: “Running out of fuel as the plane tires touch the ground is not smart.”

To me this is the take away comment - just because something can be done does not make it the right thing to do. A BCD, used properly and as all the main training agencies instruct it, is a very useful tool and a safety device (some instructors might not teach its use correctly which is a different issue). Over my dives at the weekend (to various depths upto 20m) I reckon I only filled my BCD a few times and probably only to 1/4 full but had I had to use my lungs for that it would have made the diving very hard, potentially dangerous (my lungs would have been near capacity to maintain position just of the bottom so little margin for error should something like a fin strap breaking or cramp which could limit my or my buddies capacity to swim up). Why swim so close to the edge when there is a device to aid me?

 

[REVAN]

Congratulating yourself? Really?

The congratulations was for you.

 

[soggybadger]

That's not how it read.

 

[REVAN]

A quote from the movie Deepwater Horizon comes to mind: “Running out of fuel as the plane tires touch the ground is not smart.”

All good points, but the quote is not particularly relevant, as this would be analogous to running out of air as the diver surfaces. Weight is not "consumed" like fuel.

I never said that teaching good weight management without a BC is the only way to learn. I do think it would be the most direct path simply because it has a strong "stick and carrot". Big benefits for getting it right, and a stick when not right; too light and your dive is cut short by excess buoyancy, too heavy and your dive is cut short from excessive air use trying to stay off the bottom. The lesson is learned quickly and with direct feedback that is balanced in both positive and negative weighting errors. The BC makes this a one sided lesson that biases toward being to heavy, and that makes it more difficult to sort out "right" from "excessively heavy, but not so much as to cause major issues".

To break the circle of arguments, let's just say that the no BC training is not going to happen. What are the other options?

I like the drills you discussed with using lung control to maintain buoyancy while moving weights. Is this a part of standard OW training (it was not when I was first certified in back in 88)? If so, are there some training agencies that are specifically not doing this? While useful, it does not have a direct feed to penalizing overweight conditions. How does the student learn if they have too much weight other than the effects of buoyancy instability which not show with a large effect until the weight gets pretty far out of wack (probably on the order of 8 to 10 pounds or more).

If these drills are standard, then why are weight management skills still at the top of the list for needed improvements? What else is needed? Is there any drill to make weight management lessons balanced in both positive and negative directions when the student has a BC?

 

[stuartv]

All good points, but the quote is not particularly relevant, as this would be analogous to running out of air as the diver surfaces. Weight is not "consumed" like fuel.

I like the drills you discussed with using lung control to maintain buoyancy while moving weights. Is this a part of standard OW training (it was not when I was first certified in back in 88)?

Gas carried is weight and it is consumed like fuel.

He said the drills are ones he uses when teaching an Advanced Open Water class.

 

[wetb4igetinthewater]

If these drills are standard, then why are weight management skills still at the top of the list for needed improvements? What else is needed? Is there any drill to make weight management lessons balanced in both positive and negative directions when the student has a BC?

Many instructors are lazy and stick way too much weight on their students and plant them on the bottom of the pool. I think my OW certification was a sampler. For example, I did not do one single hover exercise in the pool or in the open water. Just on my knees. Only time I got off my knees was to do a CESA (not even sharing air and ascending).

So, I would see as a first step is that all agencies teach students while neutrally buoyant. And it isn't hard to do with the first pool session / open water dive. Lots of instructors do it. And as part of that first step, all instructor examinations would be performed neutrally buoyant. I'd like to see that all instructors are also retested to demonstrate skills while neutrally buoyant, but we all know that will never happen.

While there are other training deficiencies that need to be addressed, the neutral buoyancy one is where I'd like to start. Let's make that a global standard and then move to the next lowest hanging fruit.

 

[boulderjohn]

If these drills are standard, then why are weight management skills still at the top of the list for needed improvements? What else is needed? Is there any drill to make weight management lessons balanced in both positive and negative directions when the student has a BC?

The drills he mentioned are not standard. There are many drills that different instructors have used to have students learn buoyancy control. I already mentioned the reason I believe that being overweighted is at the top of the list of needed improvements--scuba skills are still taught primarily to students who are kneeling at the bottom of the pool rather than horizontal and neutrally buoyant. In order to teach students in that manner, they must be heavily overweighted to keep them from constantly bouncing around and tipping over. If the instructor has to have the students that much overweighted, they are not going to be able to do the drills that Colliam7 described.

Years ago I did a week of diving in Ste. Maarten, and I got to know the staff of the shop I was using well. On one dive I saw one of their instructors working with someone who was supposed to be an AOW student, but what I saw was a very basic buoyancy exercise. I asked about it after the dive, and the instructor told me that the student had asked for an unreal amount of lead to begin with, and she had talked the student down to something more reasonable. In the water, she saw that the buoyancy skills were so very bad that she abandoned the planned dive and worked on that instead.

By an incredible coincidence, when I flew home, I found myself sitting next to that student, and we talked about her experience. She had learned to dive through a Sport Chalet shop in California, a chain that is no longer in existence. In the pool, they gave every student 20% of their body weight, meaning that they had put 20 pounds on her 100 pound body. I said that I could not believe they could do any of the buoyancy skills with that much weight, and she said they couldn't--none of the students could do any of them. The instructor explained that achieving proper buoyancy was an advanced skill, and they were therefore excused from meeting any of those standards.

Please note that in doing what he did that instructor violated several standards. Students are required to do weight checks and be properly weighted. Students are supposed to do the required buoyancy skills. (Those requirements have been beefed up in the last couple years.) Because he wanted students firmly planted on the bottom, he was willing to violate those standards.

The solution is simple: teach properly equipped students who are weighted correctly, neutrally buoyant, and in the same horizontal trim they will be in when they dive. As long as students are taught on their knees, correct weighting will be a problem.