Too much lift?

[The Chairman]

Over weighting IMO is mostly a result of too many instructors and dive ops relying on sloppy rules of thumb like "10% of your body weight" in lead.

When I became a NAUI Instructor near the turn of the century, student control was a major part of our learning. The stress was on kneeling, kneeling, kneeling in order to keep them under control. We were taught how to weight students correctly and then we had to make sure we overweighted them so they could kneel properly. During one test, I was tasked with teaching mask clearing at King Springs in Crystal River. The area I was given to do this was particularly silty and seemed to be an amalgam of vegetative debris mixed with fish poo. I was absolutely neutral as were most of my ersatz students. Only the over weighted could successfully kneel and our attempts to kneel while neutral produced clouds upon clouds of fish poo. I was surprised the EPA didn't show up and I never made that mistake again. Though I was taught a super simple and easy way of weighting students correctly, I was also taught to systematically overweight them in the name of safety. We were dinged for overweighting them as well. Confusing? You betcha. It's not just NAUI. It's not just PADI. It's not just SDI. It's none of them and it's all of them. I can tell you, if the instructors are conflicted and confused teaching kneeling students, the students are even more so.

I've seen a lot of changes with instruction in the last twenty years, and I expect we'll be seeing even more. The over weighting issue isn't "sloppy": it's endemic. It's going to take time to get everyone off their knees and I hope to be a part of the driving force for that.

 

[cool_hardware52]

I've seen a lot of changes with instruction in the last twenty years, and I expect we'll be seeing even more. The over weighting issue isn't "sloppy": it's endemic. It's going to take time to get everyone off their knees and I hope to be a part of the driving force for that.

It's also sloppy. When a diver walks into a shop to rent gear and the clerk asks "what do you weigh?" and then grabs a weight belt off a hook based on only that info it's sloppy.

I've witnessed this multiple times. Zero effort made to learn what wetsuit, what tanks, etc. Just give 'em plenty.

I asked a shop owner if he was at all concerned about dangerously over weighted customers. His response was "they are certified, they signed a release, and they get mad if they can't get down." SMH.

I first learned to dive before the advent of BC's It was all about weighting. Nobody wanted to tread water 10-15 lbs negative.

Then came BC's and one could be ~5 lbs negative without much burden.

Then came *HUGE* BC's and it became easier to pass out 18 lbs weight belts that to educate.

Tobin

 

[TrimixToo]

I first learned to dive before the advent of BC's It was all about weighting. Nobody wanted to tread water 10-15 lbs negative.
Tobin

Yup. Neutral at 15' (in a wet suit) was what we were taught. Made you heavy at the bottom, though. BCs are much better. (Along with things like SPGs, power inflators, computers, etc.)

John

 

[cool_hardware52]

Yup. Neutral at 15' (in a wet suit) was what we were taught. Made you heavy at the bottom, though. BCs are much better. (Along with things like SPGs, power inflators, computers, etc.)

John

BC can be a huge benefit. I do after all design and sell BC's.

That does not however preclude them from having negative impacts too, and routine over weighting is one of those consequences.

Tobin

 

[The Chairman]

I first learned to dive before the advent of BC's

As did I and my first dive was in Lake Underhill, Orlando Florida, the summer of 1969, with a harness made out of rope. I never needed weights until I started wearing thermal protection and the BC had nothing to do with it.

So, we differ on why we believe over-weighting exists and is prevalent. Your opinion seems to be deeply rooted in the fact that you make your living on selling wings. Mine is deeply rooted in being an instructor and having gone through numerous IDCs. Personally, I'm not a huge fan of the BP&Wing for single tanks. I dive a hybrid instead for single tanks. I dive a 55 lb dual bladder for my rebreather and doubles and a 50 pound double bladder on my sidemount.

I don't share your view that BCs encourage bad weighting practices. I feel that's inherent in the old style of teaching on the knees. It's also my belief that people want BCs they can dive at home in colder waters as well as on vacation in warmer climes.

 

[cool_hardware52]

As did I and my first dive was in Lake Underhill, Orlando Florida, the summer of 1969, with a harness made out of rope. I never needed weights until I started wearing thermal protection and the BC had nothing to do with it.

I've never said a BC *requires* more ballast. I've been pretty clear that BC's permit / allow over weighting. I'm puzzled that you continue to claim otherwise.

So, we differ on why we believe over-weighting exists and is prevalent. Your opinion seems to be deeply rooted in the fact that you make your living on selling wings.

Pete, if you haven't yet figured it out, I make my living in a variety of ways. Designing and selling BC's is something I do because I enjoy it. I'm not sure why you continue to attribute motives that don't exist. I've always made every possible effort to provide my customers the *why* behind my recommendations, and I've always been entirely willing to decline sales I thought unwise.

In Southern California, which was a center of scuba innovation and training, it was routine for divers to use wetsuits and no bc's. Water temps in the 50-60 make exposure suits more or less mandatory for anything other than very short exposures.

Vintage divers continue to dive in cold water with thick suits and no BC's They do so by carefully managing their ballast.

Scuba *with* fairly buoyant exposure suits predate BC's by many years. Rolling up your "1/4" wetsuit (with duck tail) and determining exactly how much lead was needed to sink it was common practice.

After the advent of BC's it no longer is. Makes me go hummm.

Tobin

 

[TrimixToo]

BC can be a huge benefit. I do after all design and sell BC's.

That does not however preclude them from having negative impacts too, and routine over weighting is one of those consequences.

Tobin

I was not attempting to argue with your main points. I was just trying to say that when properly weighted in a wet suit, having a BC is still a big a improvement over the old way I was originally taught. If I still dove wet, I'd probably still aim for neutral at 15'...but hovering off the bottom (or the wreck) is easy with a BC and more difficult without one.

John

 

[RayfromTX]

Two people that I respect and admire think that they are in disagreement but I think it is a matter of interpretation and innacurate extrapolation of the other's meaning. When I read the last few posts I found you both to be in agreement on whether BCs require overweighting (they don't) and I didn't hear the questioning of motives.

I have learned so much from both of you. Perhaps I'm naive and not understanding what I'm reading but don't you both agree about a need for appropriate weighting, give or take 2 Kgs and don't you both agree on where the overweghting comes from? The difference is that Tobin stresses that the bc makes it easier to be overweighted and doesn't want his product to be used to enable the practice. Pete wants to eliminate the instruction methods that lead to the practice. Both of you are pushing to make diving safer and both of you are doing it for the right reasons. Bravo

 

[The Chairman]

I'm puzzled that you continue to claim otherwise.

Tobin, I'm not sure why you feel a need to be so defensive, but it is tiresome. I've read that statement I made over and over and I can't see where I claim you said anything.

Pete, if you haven't yet figured it out, I make my living in a variety of ways.

Again, I don't understand your defensiveness. You are responding like I've insulted you and for the life of me, I can't see where I've done that here. I don't believe I "claimed" that you only make money off of BCs: only that they are a source of income and that you view them differently than I do.

Your experiences seem to stem from the California diving scene. My experiences are from the Central Florida diving scene. I don't see one as superior to the other, though I prefer diving in Florida over California, especially since you don't have caves there.

 

[cool_hardware52]

Tobin, I'm not sure why you feel a need to be so defensive, but it is tiresome. I've read that statement I made over and over and I can't see where I claim you said anything.

Again, I don't understand your defensiveness. You are responding like I've insulted you and for the life of me, I can't see where I've done that here. I don't believe I "claimed" that you only make money off of BCs: only that they are a source of income and that you view them differently than I do.

Whether or not we agree on the effect of BC's on the prevalence of over weighted divers there remains no need to assign motives. None.

Your experiences seem to stem from the California diving scene. My experiences are from the Central Florida diving scene. I don't see one as superior to the other, though I prefer diving in Florida over California, especially since you don't have caves there.

The physics remain the same worldwide. Buoyant suits require ballast, and BC's encourage the use of too much ballast.

Are properly sized BC's a net benefit to diving? I would suggest they are.

Are undersized BC's an un necessary risk? Yes, clearly.

Are oversized BC's needed or offer additional benefits beyond that of a properly sized BC? I'd suggest they create at least as many problems as they solve.

If backpackers started attaching huge helium balloons to their packs I'd venture a guess they'd be less focused on lightweight gear too.

Tobin