How did quick release belts become a safety standard?

[Akimbo]

…You should not rocket to the surface when you have lost a weight belt at depth, if you are diving wet...

This is the result of my experiments, but I encourage everyone to do their own — for the experience and because “your mileage may vary”. Start by dropping something small like 5 Lbs or 2 Kg. Increase the amount you drop until you no longer feel comfortable controlling it. Wet or drysuit doesn’t really matter and 30 Ft/10 Meters is enough… just remember to exhale.

I have experimented with how much weight I can drop and still have decent control in an emergency ascent. These tests were done when the Navy ascent rate was 60'/minute, which I would happily do today in an emergency. I gradually moved up to 10 KG/22 Lbs where I felt that more would be too hard to control…

Like TSandM, I add weight to cylinders when more weight is needed than I like putting on the belt, or for trim. I find a belt heavier than 22 Lbs/10 Kg is a PITA to deal with on deck, unless you use a weight harness. I also find that it is about the maximum weight a rubber belt can take before stretching too much.

 

[Nemrod]

We did not drop a weight belt at depth in the Pre-BC era. There was no need to as any diver then would have been weighted near neutral at depth. We practiced weighting to be slightly negative below fifteen to twenty feet (wet suit crush depth) at the beginning of the dive (thus we swam down) and depended upon the increasing buoyancy of the tank over the course of the dive as air was depleted to reach a sweet spot of neutral buoyancy (and thus we swam around) and toward the end of the dive become slightly positive (and thus we swam up). Dropping a weight belt was done on the surface, if needed, to establish significant or at least greater positive buoyancy during an emergency to assist a rescue tow from a buddy or to give a tired diver a better chance at survival. The Rubatex G231 suits then available were not as prone to crush and retained more buoyancy (and warmth) at depth.

There was a reason that early divers were water people and strong swimming skills an absolute requirement. Now, there are actually people on this board who argue the opposite and the fact is, most divers actually cannot swim though many think they are good swimmers, they are not.

And that is a leading cause of drownings. It seems males are many times more likely to drown than females. Studies indicate that men in particular think they can do things they cannot, like being a good swimmer when any fair observation would reveal they are not even good at the dog paddle, which by the way, is not a swimming stroke and does not count as swimming, nor does the back flopping/float.

N

 

[boulderjohn]

If you read accident reports, you will see a fair number of incidents where a diver made it to the surface, and subsequently sank again and was lost.

In many of these discussions, we talk about the situation with the assumption that the diver is properly weighted. That is a pretty big assumption. Let's look at the situation above and analyze.

To be properly weighted, a diver is supposed to be able to drop all air from the BCD, hold a normal breath, and float at eye level without moving. That is usually done with a full tank, with different people having different theories about how much weight, if any, to add to compensate for lost air weight during the dive. Give that diver an empty tank after an OOA emergency, and the diver should have no trouble staying on the surface. In fact, the diver should find it hard to descend. A diver who cannot stay afloat on the surface with an empty tank despite his or her best physical effort to stay afloat must be significantly overweighted.

---------- Post added August 1st, 2014 at 07:42 PM ----------

My point above is that I think a major problem we have in diving is the degree to which too many divers are so very much overweighted. I could start a thread dedicated to overweighting horror stories, and I am sure it would go on for hundreds of posts.

 

[lemke]

Weight belt... what weight belt?

 

[dumpsterDiver]

In many of these discussions, we talk about the situation with the assumption that the diver is properly weighted. That is a pretty big assumption. Let's look at the situation above and analyze.

To be properly weighted, a diver is supposed to be able to drop all air from the BCD, hold a normal breath, and float at eye level without moving. That is usually done with a full tank, with different people having different theories about how much weight, if any, to add to compensate for lost air weight during the dive. Give that diver an empty tank after an OOA emergency, and the diver should have no trouble staying on the surface. In fact, the diver should find it hard to descend. A diver who cannot stay afloat on the surface with an empty tank despite his or her best physical effort to stay afloat must be significantly overweighted.

---------- Post added August 1st, 2014 at 07:42 PM ----------

My point above is that I think a major problem we have in diving is the degree to which too many divers are so very much overweighted. I could start a thread dedicated to overweighting horror stories, and I am sure it would go on for hundreds of posts.

I think a diver with a medical emergency, or in a state of panic can get in serious trouble at the surface, even if he is not "over"-weighted. If the sea state is rough, it is easy to inhale a couple hits of water. Once that happens anyone/everyone is in panic mode or close to it. It is important to be able to attain CONSIDERABLE buoyancy at the surface when things go south.

I'm not convinced that a properly weighted diver, who has an empty (light) tank is necessarily going to be fine without ditching lead and without inflating a BC. This is one of the reasons I always wear a snorkel on my mask. (more old school habits)

We should also consider the possibility that the diver has picked up some lobsters or scallops or something that might be weighing him down. The diver could also reach the surface with a full or nearly full tank, but be unable to use it, say the valve is off..

Also, in some conditions a diver needs to be over-weighted,,, say a shallow dive in a strong river or stream.. There are just many situations I can envision where a properly weighted diver might really NEED to ditch some ballast at the surface if they can not, or will not inflate the BC.

 

[beanojones]

In its new standards, PADI does require that students practice ditching weights on the surface to achieve positive buoyancy.

Which is surprising difficult to teach when people are not wearing weight belts that have more negative buoyancy than the swing of buoynacy from the air in their lungs. Teaching people to establish positive buoyancy with a weight ditch is a good plan, that teaches basically nothing if the diver is properly weighted in warm water.

Luckily(?) most divers are far from properly weighted in warm water.

If you read accident reports, you will see a fair number of incidents where a diver made it to the surface, and subsequently sank again and was lost. One of the most important skills in the Rescue class is pulling a disabled or panicked diver's weights, to render them permanently buoyant and to aid with rescue.

You mention that many things are built around warm water thin wetsuit diving, but this bit is hard: relaxed correctly weighted divers are not wearing enough weight to actually make them positively buoyant even on the surface to any degree.

One of the reasons that a lot of discussion is past each other, on many issues is, for instance the fact that "properly sized" wings for cold water diving do not provide enough bouyancy at the surface in many conditions in warm water gear, because our exposure protection often has very little inherent bouyancy, so a full small wing is not actually very positively buoyant.

Why I like the OMS's enormous twin bladder 100 lb lift bungied wings is for that reason, positive buoynacy on the surface, and bungied smallness under water.

---------- Post added August 1st, 2014 at 10:48 PM ----------

I think a diver with a medical emergency, or in a state of panic can get in serious trouble at the surface, even if he is not "over"-weighted. If the sea state is rough, it is easy to inhale a couple hits of water. Once that happens anyone/everyone is in panic mode or close to it. It is important to be able to attain CONSIDERABLE buoyancy at the surface when things go south.

This and especially since the diver starts sinking once they start coughing away their lung buoyancy.

 

[TSandM]

To a point, I agree with you, beano. An empty Al80 is about four pounds positive. A jacket BC is about 2 to 3 pounds positive, and a 3 mil wetsuit is maybe 4 or 5 pounds positive. So the maximum you can be is maybe 10 lbs positive -- which is CERTAINLY enough so that you won't sink inadvertently.

However, construing that to mean you need a 100 lb wing in warm water is ludicrous. Nobody needs 100 lbs of lift, period -- but certainly when the maximum amount NEGATIVE you can be, properly weighted, is about six pounds, you certainly don't need a lot of lift. I have dived in warm water, with an Al80 and a 3 mil suit, with a 17 lb wing, which was PLENTY of lift, even with my weight belt ON.

In cold water, you may need more lift, because you have more buoyancy to lose. At depth, a 7 mil suit can lose up to 20 lbs or so of lift; my fully flooded dry suit had certainly lost that much. A full 100 cf steel tank is about 8 lbs negative, too -- so flooding a dry suit early in the dive can require a TON of lift on the surface.

I do not get your reasoning about huge lift in warm water, not at all.

 

[beanojones]

People dive in wetsuits and standards 80's without weights all the time, because there are a ton of people who only float when their lungs are bursting full, and that's just to keep just their lips clear of the water, which is hardly a safe condition to be in the water even when it is as still as a lake.

I sink my gear and intro divers gear when I am not using it all the time. I only use al80 and al63s. So the only postiive buoyancy possibly available is the exposure protection. (Not everyone uses postive buoyancy exposure protection.)

So there is any real amount of positive life available except through a high lift BCD. More importantly, in a rescue situation 10 pounds positive buoyancy won't keep the airway clear, in real ocean conditions. In six foot rollers, with chop and spray, I want that victim on a boat, but until they are on the boat, I want the next best thing. I want their head well clear of the water.

The head clear of the water? Isn't that too bouyant?

Now imagine the typical upright panicked diver whose mouth in at the bottom of their face, mostly. The mouth is not at eye level.

If they suck water and start choking they get negative, because they lose their lung buoyancy. The only thing they need when choking is their head well clear of the water so they can stop panicking. That is to say, a high lift BCD is needed.

Notice at this point we have not even covered the fact that the panicked bicycle kick of a diver at the surface can become a kick that pulls them down with a fair amount of force. If you have not seen this happen, then I am glad for you. But divers exerting more leg effort resulting in more downward pull from the top upper surface of the thigh being brought up violently parallell to the surface is just a basic part of a rescue course, at least where I am from. It's why the most experienced diver should be the victim, because it is hard to dive badly until you have seen just how badly people can dive when panicked. Panicked means nothing effective, and much counterproductive action. Rescuing a diver is not about how we think they should be diving, but how to remove them from danger with as little fuss as possible. Thus high lift BCDs which immediately solve surface problems. Because the weight belt drop does not do poop.

Huge amounts of lift is ludicrous and unnecessary until it is needed, and then it is just silly to have thought that avoiding using high lift BCDs is a good idea, simply because somebody on the internet said they were ludicrous. I am happy to be though of as ludicrous, then. In a drysuit you are wearing a tool that might give 30-40 pounds of lift plus the BCD lift. In the tropics we don't have that. We only have the BCD.

We can dive with minimal gear when we are playing around. I dive with tanks and no BCDs all the time. But those are specifically FU dives because I am not even slightly available to other divers. in any sense.

When I am in charge of divers, especially when there are intro divers, making me or them immediately enormously positively buoyant is a requirement for safety, because until their head is well clear of the water there is no solution to panicking and choking.

That is after all why we define confined water as water in which we can immediately stand up, because head clear of the water in necessary to calm people down.

I get that people should be able to blah blah blah. In the real world, once someone panicks, we cannot worry about what we want them to do. We can only do our job which is to remove them from danger as soon as possible, with an minimum of fuss, so they can calm down and maybe won't drown, or more practically maybe won't decide to never dive again. Because professional.

Thus high lift BCDs. As ludicrous as you may think they are.

 

[lowviz]

...//... In six foot rollers, with chop and spray, I want that victim on a boat, but until they are on the boat, I want the next best thing. I want their head well clear of the water.

Yeah, I know, 3 to 4 with six foot rollers, as in everyday. I'll be on a newbie dive in just those conditions in a week. Christ, stop watching reality TV.

...//... The head clear of the water? Isn't that too bouyant? ...//... When I am in charge of divers, especially when there are intro divers, making me or them immediately enormously positively buoyant is a requirement for safety, because until their head is well clear of the water there is no solution to panicking and choking.

Must admit you got one hell of a skill set for an instructor, maybe you should talk to T. C., he self-admittedly would just punch them in the face.

...//... We can only do our job which is to remove them from danger as soon as possible, with an minimum of fuss, so they can calm down and maybe won't drown, or more practically maybe won't decide to never dive again. Because professional.

Can't argue with that, I not professional.

...//... Thus high lift BCDs. As ludicrous as you may think they are.

ScubaPro "Classic" vest BC. You float like a freaking cork, upright, and they aren't even terrible U/W. Reasonable lift.


Seriously, are you really an instructor?

 

[TSandM]

If you are taking new divers with horrible skills and anxiety problems into conditions where they need 100 lbs of lift to be able to breathe at the surface, the problem is not the BC.

I can get my whole head out of the water with my 17 lb wing, and I could do it without the 4 lbs of lift of a 3 mil wetsuit, too.

I recognize that leading tours of poorly trained novice divers is not the diving I do. But if the only way to keep them safe is to put crazy big BCs on them and blow them up, then honestly, how can you morally and ethically do that work?

I also find it difficult to believe that anybody can bicycle kick themselves DOWNWARDs when their fins are beneath them. All our dive 1 students bicycle kick at the surface. Most of them find it quite difficult to descend while doing so.