Ankle floats?

[UCFKnightDiver]

In fact, a properly weighted recreational diver should have trouble descending with an empty cylinder.

I liked most of your post but I don't agree with the last line. I personally believe that a properly weighted diver should not have much trouble descending with an empty tank/500 psi. If you can't VERY easily kick down with an empty tank then you are not properly weighted in my opinion. In fact, that's one of the concerns/beefs I have about some instructors having a bit of an obsession with using as little weight as possible (not you necessarily). If you are underweighted and cannot hold a safety stop with an empty tank, or worse you cork to the surface, that's a seriously big problem and is much worse than being a couple pounds overweight.

 

[dmaziuk]

The most common cause of deaths was medical, usually a heart attack, with symptoms very sudden, with the diver either making it to the surface or passing out and dropping unconscious to the bottom.

True story: the rubber disk in my wife's BCD's shoulder dump valve got unglued. It must've got stuck at an angle when she was venting during the dive, leaving the valve partially open. She surfaced and all of a sudden her BCD wasn't holding air. I was some 4' below her so I didn't see any of it, and the DM was some 4' away busy with something else. She asked for help and it took him some 40 seconds to turn his attention to her; she had very stressful 40 seconds fining to stay afloat, drained her tank trying to figure out what's up with the BCD, adrenaline rush, all that. I later asked why she didn't ditch weights, she said she was coming to that when the DM finally turned to her and gave her a hand.

Point being, I wouldn't be too surprised if someone in a bad physical shape and with bum ticker had a heart attack in those 40 seconds.

 

[wetb4igetinthewater]

one of the concerns/beefs I have about some instructors having a bit of an obsession with using as little weight as possible

 

[lowwall]

???

If dropping weight isn't a core survival skill then why waste time doing it at all?

The WRSTC minimum standards for open water diver includes a requirement to demonstrate the skill of "Underwater removal and replacement of the weight/ballast system". This makes sense since the diver is likely to have to use weights at some point, even if it's not needed in the OW class.

But having to demonstrate that skill is no excuse for forcing a student to be overweighted for the remainder of the class.

 

[UCFKnightDiver]

You missed some of the relevant parts there.

 

[boulderjohn]

I personally believe that a properly weighted diver should not have much trouble descending with an empty tank/500 psi. If you can't VERY easily kick down with an empty tank then you are not properly weighted in my opinion. In fact, that's one of the concerns/beefs I have about some instructors having a bit of an obsession with using as little weight as possible (not you necessarily). If you are underweighted and cannot hold a safety stop with an empty tank, or worse you cork to the surface, that's a seriously big problem and is much worse than being a couple pounds overweight.

You do realize that there is a pretty big difference between being completely OOA and having 500PSI, don't you? I do understand that 500 PSI in an AL 80 is only about a pound, but it is a pound nonetheless.

I prefer to dive a few pounds overweighted on a recreational dive myself, but let's look at the standard definition of proper weighting. A properly weighted diver with a full tank should float at eye level with the BCD empty while holding a normal breath and not kicking. That is a standard test for weighting. If an AL 80 holds 6 pounds of air, and if those 6 pounds of air are removed, then a diver with 6 extra pounds at the start of a dive should be able to float at eye level without kicking with an empty cylinder. If you have a few pounds more than that, you should be able to stay afloat with easy, lazy kicks.

When I teach an OW confined water class, I am typically about 6-8 pounds overweighted intentionally, so that I can descend quickly if needed. I do the following demonstration for the effect of breathing on the diver. Near the bottom, I dump all air from the BCD to settle to the floor of a 12-foot pool. I them inflate with a random shot of air. I then inhale to make myself rise off the bottom. I then use a series of inhalations and exhalations to rise all the way until my head breaks the surface. I then reverse the process, using a a series of exhalations and inhalations to descend slowly to the bottom. That is all done while overweighted by 6-8 pounds, and it is done at altitude. (I can explain the difference is you like.)

So I will repeat my claim--a diver who cannot stay on the surface with vigorous kicking with an empty cylinder is grossly overweighted.

 

[UCFKnightDiver]

So I will repeat my claim--a diver who cannot stay on the surface with vigorous kicking with an empty cylinder is grossly overweighted.

You actually said the opposite. You said a properly weighted diver should have trouble descending with an empty tank. I agree with the quote above that you shouldn't have trouble staying on the surface if properly weighted either. I also agree that if you are properly weighted that you should float at about eye level with an empty tank, but none of this is what I took issue with...

 

[boulderjohn]

I was summoned into this thread well past its beginning and responded to the specific summons without reading the first part of the thread. Mea Culpa. I will make a few comments about the main topic, which I had no knowledge of when I foolishly stepped in from out of the blue.

As an instructor in pool sessions, I have frequently had students who did not need any weight at all for diving in a freshwater pool with a 3mm suit. Some athletic males in particular were "overweighted" with no weight. Children commonly needed no weight. When I was using a 3mm shorty for instruction, I really didn't need any weight, either. I needed a couple of pounds with a full suit. In my early days of instruction, the problem was dealing with skills like weight belt removal and replacement, so I had them wear minimal weights, just so they could do the skill. Then PADI added trim weights and and weight belt drop to the OW class. The trim weights were a real problem, because I had to put 4 separate weights on people who do not need weights. The weight belt drop was not a problem. I had a separate weight belt on the side of the pool so they could use it for that skill and be done with it.

So why teach weight belt (or weight pocket) skills to students who don't need it? Because someday they will. Diving in the ocean requires more weight than diving in a pool. Weighting needs vary. I personally rarely use ditchable weight, but it is good to know how to use it. For the most part, though, students should not get more weight than they need, and they should learn to dive properly weighted.

When I was doing one of the dives for my IDC off of a dive boat in Key Largo, I saw a woman literally crawling across the sand with what had to be 25-30 pounds bulging out of her weight pockets. The look in her eyes was pure agony. At that moment I swore my student would never look like that.

 

[boulderjohn]

You actually said the opposite. You said a properly weighted diver should have trouble descending with an empty tank. I agree with the quote above that you shouldn't have trouble staying on the surface if properly weighted either. I also agree that if you are properly weighted that you should float at about eye level with an empty tank, but none of this is what I took issue with...

I guess I missed your point. I was suggesting that if with a tiny shot of air in the BCD I could stay on the surface without kicking while 6 pounds overweighted and with a nearly full tank, then a diver who cannot stay on the surface while vigorously kicking with an empty tank has to be grossly overweighted.

 

[MichaelMc]

OP, I applaud your efforts to get to a neutral weight distribution (in trim). It makes diving much easier.

- The puffiness of your BC shoulder padding is making it harder. Being lighter than the water it is pushing up on your shoulder and chest area, pushing your hips and legs down. (Of course if you get rid of that puffiness you will need even less lead than zero, but at least it will not be pushing your shoulders up.)

- I agree adding weight so you can ditch it is mostly nuts. Once past the issue of initially being trained how to ditch if you needed any weight to begin with.

- But..., being a few pounds over weighted is not a horrid thing if there are few other good choices. A few. Say 3-4 pounds. So, some weight on your shoulder straps high up seems like it will get you to a workable state. The suggestion of how to bungee cord it to the straps is good. There are also various trim pockets that work well there and open easily to ditch if desired. One is the XDeep trim pockets. Unfortunately most really only work on 2" webbing of a BP/W.

- And forget about using the trim pockets part way down the back or any hip integrated pockets, they are not helping.

- Overall a BP/W with an aluminum or cutout steel plate would be your friend. You would still likely be putting any lead high up on your body on the shoulder straps, but they are better setup for that than most, or any, all in one BC.
DGX Custom - DGX Singles Harness / Backplate / Wing Package | Dive Gear Express®
They are very good for many reasons, but for your issue it mostly would just simplify the issue by removing the padding that is complicating things. You would still likely need to put some lead up high on your shoulders, or use the other ballast/buoyancy shifting suggestions such as AL63 low or PVC pipes filled with air low.

- Thinking of yourself as a see-saw is the way to go. All your parts and limbs and all your gear push down or up on the see-saw where they are depending on if they are negative or positive in the water. You just need to even it out by moving the bits you can or switching them out.

- Your class instructors do not seem to be helping the situation much.

- Welcome to the board!

- trim resources:
99 Problems....and your TRIM is one! %

This position with heels forward by the butt is what people mean by sky diver position.

ETA if you are negative, redundant buoyancy is good to have. Drysuit or redundant bladder wing/BC are best, but a DSMB for surface redundancy is helpful as well and you should have one anyway and know how to use it.