Lessons Lost integrated weight pouch at depth

[Divin'Papaw]

The Scubapro pockets are directly observable, easy to insert, and very secure. Somewhere around 2000 dives, not a single problem.

I'm very glad to hear you've had years of reliable use from your Scubapro BC. I'll stick with my BP/W. While I have found numerous ditchable weight pockets on the bottom of quarries, lakes, and the ocean, I've never found a backplate just laying there on the bottom.

 

[afdgf]

I was in the middle of a lovely boat dive in Catalina with my new buddy, a steady diver with plenty of experience. We had both dived from the Dr. Bill Casino Point the day before, so our skills were reasonably sharp. On the second dive of the day, I was at about 12 m / 40 ft., in an 8/7mm wetsuit, with a steel 12 L / HP 100, 2 lb. tank weight and 20 lbs. in the integrated "Sure Lock" weight pouches of my Aqualung back-inflate Dimension BC. That amount of weight is pretty dialed in for me, no plummet on descent but no trouble staying down at the safety stop.

Everything was going great, except that I had to dump a decent amount to stay level and was having trouble dumping enough. My breathing got unconsciously shallow as I tried to avoid taking my normal slow breaths. I swiveled around to make sure all the air in the BC was at the kidney dump, dumped the remainder, and felt around to find no bubble back there at all. Then I realized something was wrong, because there should be no way I should be light at 12m with my BC completely empty. Taking the half-full tank and wetsuit compression into account, there should be a decent-sized bubble in there, at least 1-2 L. I felt around for my weights and couldn't find the left pocket. That was my first real pucker moment at depth. The last thing I wanted to do was make a buoyant ascent. I didn't try to stop, breathe, and think like I was trained, unfortunately.

I signaled "trouble" to my buddy and eventually was able to show him the missing weight pocket, though that took a while. I wasn't quite thinking clearly with the adrenaline, I should have picked up rocks immediately, because that did weigh me down enough to be perfectly stable. It was certainly lucky that we were on a rock pile and surrounded by kelp with high tensile strength. I kept real close to the bottom and my buddy, and we basically sat at the base of a 5m stalk of kelp to take our safety stop. Then I went up as slowly as I could, grabbing the kelp as needed. All in all, a very successful ascent.

Lessons learned

1. Don't rely on Aqualung "Sure Lock" weight pouches. I did not notice losing the weights; possibly when another diver veered into me? We had 20 divers on one three-tank trip, and lost 4 weight pouches among us, all from Aqualung. The design of ditchable weight is tricky since you have an "always/never" situation where you want the weights to always be ditchable when needed, but never do so accidentally. This accidental weight release was in a very benign environment, with extra weight in the form of rocks, at a moderate depth, with kelp, and with a solid buddy. If it had been midwater, deep, no kelp, and a flaky instabuddy, the results could have been negative (no pun intended). It seems like what you really want is 10 lbs. non-ditchable and 10 lbs. ditchable in 5 lb. increments. I really can't think of a situation where you'd want to ditch it all, even if you had a busted BC, completely full tank, no hard bottom, and needed to CESA. Time to get a backplate so I can make that choice, I guess.
2. Always check your weights and your buddy's weights before every dive, not just the first. I had checked my weights by listening for the solid "click" and pulling on them firmly at the start of the first dive and did not touch them afterwards (I notice many divers remove them to replace tanks, in which case you'd obviously have to redo the check). I don't remember doing a check immediately before the dive with the incident. My buddy gave a more than cursory check, but I don't think he tugged them either. My guess is the pouch was secure when I started the dive and just got snagged against a rock or the other diver.
3. Always leave a good gas reserve, appropriate to the conditions. Having several minutes to resolve the problem let me calm down a bit, remember to pick up rocks, and communicate with my buddy.
4. If you do have a Sure Lock, a spare should be part of your Save-a-Dive kit. There are two sizes, one for the jacket, the other for back-inflate, but the shorter back inflate version (that only holds 10 lbs.) fits in both. So you can save your own dive, or have your drinks bought by a grateful buddy.

I had a weight pocket fall out of my Black Ice and I could not figure out why I was having so much trouble descending. Then I saw it laying on the bottom, but it was only about 25-30 feet and very clear vis. My buddy saw what was happening and I pointed to the weight pouch and she went and got it and I put it in and continued the dive. Both of us always take spare pouches with us when we travel. When empty, they are very light and do not cause problems with making weight on the airplane. We were on a crowded boat and I think the person next to me hit the weight pouch.

 

[Belzelbub]

The Scubapro pockets are directly observable, easy to insert, and very secure. Somewhere around 2000 dives, not a single problem.

As is the Zeagle Ripcord system. Insertion isn't the right word though, as you just drop into the pocket. Not quite as many dives as you, but still more than a handful. Only one incident, and it was entirely my fault, and able to be corrected easily during the dive.

I forgot once to close the zipper on one of the weight pockets. Did a backroll entry, and when I got to the bottom, saw a soft weight just like mine, then a second one. I realized then that they must actually be my weights. Placed them back in the pocket and closed the zipper to continue the dive. That was very early with this BC. Since then, I've made sure it's completely closed before splashing, and no further issues with my BC, my daughters' BCs, or the Aquarium's BCs that are identical to mine.

 

[inquis]

Did a dive in Cozumel where my buddy forgot all 10 lbs of his weight. 5 lbs of unbreathed air and 5+ lbs of suit compression meant he was neutral at depth. Combined with a hot drop, he simply didn't notice right away. We then made a normal ascent with a safety stop, and we had enough air remaining to be neutral (with me lightly holding onto him). The final ascent to the surface wasn't as slow as normal, but with both breathing shallow it was controlled and safe.

Lesson learned: buddy checks are still important even a week into a marathon dive fest and even on the second dive of the boat outing.

 

[wnissen]

I think you are incorrect. What size rock does the diver need to carry to offset the loss of 10 lbs of lead???

I did the math, but I am a little rusty on it. I have carried rocks quite a few times when too light. It actually works quite well.

That's a pretty easy calculation. Let's say we need 4 kg / 9 lb. of weight, since we can use our breath and maybe some gentle kicking to make up for the remaining bit. Since many ocean floors are made up of limestone, the density (according to Wikipedia) ranges from 1.5 to 2.7 kg/L, an average of 2.1 kg/L. That's a net density of 2.1-1.0 = 1.1 kg/L. So to get the necessary weight you need 4/1.1 L of rock, or 3.6L. The necessary rock is smaller than a gallon jug of milk, or a pair of 2L soda bottles.

 

[johndiver999]

That's a pretty easy calculation. Let's say we need 4 kg / 9 lb. of weight, since we can use our breath and maybe some gentle kicking to make up for the remaining bit. Since many ocean floors are made up of limestone, the density (according to Wikipedia) ranges from 1.5 to 2.7 kg/L, an average of 2.1 kg/L. That's a net density of 2.1-1.0 = 1.1 kg/L. So to get the necessary weight you need 4/1.1 L of rock, or 3.6L. The necessary rock is smaller than a gallon jug of milk, or a pair of 2L soda bottles.

thanks.. Easy for you... But that looks similar to what I determined last night - not a big rock at all - EASY to carry in one hand.

Hopefully nobody has to use it, but I would hate to think that somebody would not try it, simply because they had a misconception about the practicality of it.

As was described in an earlier post, it is not that hard to power down to depth after forgetting to bring your lead. I've done it a month ago, I think. Luckily, I only wear 6 lbs of lead on a belt with a 5 mm suit and a steel tank and pony, so I was able to manage the ascent with NO ROCKS, actually I didn't notice my error until I seemed a little light at 20 feet. Apparently, I am diving with 6 lbs more lead than the minimum I need to make a controlled ascent, LOL.

 

[kelemvor]

Another option for ditchable pouches that don't self-ditch is Dive-rite. I've used them for years with zero accidental ditches. I did put the pocket in wrong once, causing it to just flop around instead of being in the "slot". The clicky holder thing was strong enough to keep the weight attached to me.

I do make it a point to replace mine every 5 years. The clips are plastic, and get inserted/removed a lot. This way I don't have to worry about them letting go because they're super worn out.

They can be mounted horizontally or vertically. I mounted them horizontally on the waist strap of my bcd.

The main drawback is that they're quite expensive. About $100 if memory serves. IMO it's a "you get what you pay for" situation.

16 lb QB Weight Pocket - Dive Rite

16 lbs mounted vertical or horizontal with quick release handles.

www.diverite.com

 

[wnissen]

Ditchable lead and cold water go together very well, there was a recall on the AL sure-lost weight system was this the “improved” model?

The recall in 2014 was for the handles detaching, so you wouldn't be able to ditch. The opposite of what happened here. Though the number of lost pouches is high enough I wonder if they should recall them. I bought mine in new in 2018.

 

[wnissen]

I think that recall was on the handles breaking off. Buddy/wife has one of those. However I find that you must insert and hear/feel the click or it will fall out. I tend to double check her's

Yes, the insertion isn't as reliable as I would like, you can get them 90% of the way in and somehow still not engage the locking mechanism, which is inside the BC and not visible. I do always listen for the click.

 

[wnissen]

Another option for ditchable pouches that don't self-ditch is Dive-rite. I've used them for years with zero accidental ditches. I did put the pocket in wrong once, causing it to just flop around instead of being in the "slot". The clicky holder thing was strong enough to keep the weight attached to me.

I do make it a point to replace mine every 5 years. The clips are plastic, and get inserted/removed a lot. This way I don't have to worry about them letting go because they're super worn out.

They can be mounted horizontally or vertically. I mounted them horizontally on the waist strap of my bcd.

The main drawback is that they're quite expensive. About $100 if memory serves. IMO it's a "you get what you pay for" situation.

16 lb QB Weight Pocket - Dive Rite

16 lbs mounted vertical or horizontal with quick release handles.

www.diverite.com

Looks like the new model is this: 12 lb QR Weight Pocket Set - Dive Rite
That's about as much ditchable weight as I would want, the rest should be in on on the plate, and they're down to a bargain $70. (sarcasm) Ordering them, thanks. Do you have a recommendation for non-ditchable weight attachment?