Why would you want to dump weight?

[crispos]

No one said that you should stay plastered to the bottom if you should find yourself in that situation. Have they?

Actually, yes.

Both you and String have been arguing for over a week that weight ditch at depth is not a logical option under any circumstances.

Or have you forgotten?

I looked for the original string but it has been deleted, I wonder why.

 

[MikeFerrara]

Actually, yes.

Both you and String have been arguing for over a week that weight ditch at depth is not a logical option under any circumstances.

Or have you forgotten?

I looked for the original string but it has been deleted, I wonder why.

No I haven't. I have argued that if you're correctly weighted that you won't need to dump weight to get to the surface.

I've explained that it's an absolute last resort and even refered to training standards and how it's taught.

I'm not sure what your point is but...dive over weighted if you want and drop your weights if you feel the need.

 

[Diver294]

My dive master taught us that the WI BC was best

My OW class was taught that the WI BC's were the best bet due to the added "feature" of dropping the weight in a last resort situation. In my particular situation, being very new to diving, I have found my WI BC to be very comfortable and it has eliminated my need for a weight belt completely.

....not sure if that's the OK actually, but it works well....

 

[lamont]

I've been seriously considering reducing/eliminating the amount of ditchable weight that I carry. I dive a trilam drysuit with a halcyon eclipse wing (inner bladder) and carry an SMB, so I have at least doubly if not triply redundant bouyancy. I can also either ditch my gear or use a knife or shears to cut myself out of my gear. So what is the benefit of ditchable weight? Isn't it more of a risk that the weight would ditch accidentally and result in a runaway ascent? I guess being OOA and not being able to inflate the drysuit while at the same time having a wing failure would suck -- manual inflation of the SMB would help some there, but it'd be useful to have (cheap) weight to drop rather than to have to worry about dumping a tank (if steel and negative) or entire rig...

Does anyone know if after ditching your rig you've got a flooded trilam drysuit with thinsulate if you'll float or not? Anyone ever experienced this or tried it in a pool?

 

[miketsp]

Clear example of need to drop weight at surface:

Quote
The coroner at the inquest into the death of 41-year-old Paul Imeson, who died after a dive off Anglesey in October 2003, has concluded that he drowned on the surface.

Coroner Dewi Pritchard-Jones recorded a verdict of accidental death after hearing evidence about Imeson's death at the inquest in Llangefni, Wales.

The inquest heard that Imeson was an inexperienced diver, and had recently learned to dive on a three-day PADI course in the Caribbean. He was shore diving at Trearddur Bay with his brother-in-law, an experienced diver, and another inexperienced diver.

Imeson became distressed after surfacing in the swell and removing his mask and regulator. He appeared low in the water and was struggling to maintain sufficient buoyancy. The coroner found that he had inhaled water, passing out and drowning before his companions had recovered him onto rocks and begun attempts at resuscitation.

 

[Delta_P]

Does anyone know if after ditching your rig you've got a flooded trilam drysuit with thinsulate if you'll float or not? Anyone ever experienced this or tried it in a pool?

I was curious how my suit would behave if completely flooded, so I did this a couple of weeks ago. Trilam with 400 gm thinsulate. Hovering ~ 1 foot off the bottom, in 14' of water. Opened the self donning zipper from waist to shoulder. Cold.

DAMN COLD!

Did I mention it was cold?

"Close" does not count when you are close to the thermocline, but below it.

Because I was horizontal the incoming water displaced the air into pockets in my legs, arms, and shoulders, and my buoyancy did not change. Nada. Zip. Could have remained hovering there all day except for the minor issue of hypothermia setting in.

I need to try the test again standing vertically in the water so the air is actually purged out of the suit. I think though I'll wait until full summer sets in so I can warm up quicker on deck.


The coroner's findings mentioned above aren't that uncommon. I've seen other reports saying the same thing - victim came to the surface, struggled / was in distress, sank out of sight and was recovered later with weightbelt in place. The only reports I recall seeing where weight needed to be released at depth while sport diving were cases where the deceased was grossly overweighted to begin with, lost control of his / her buoyancy, and sank too deep too fast.

Besides giving me options at the surface, the other reason I like having ditchable weight is to save the back of the RIB operator when she has to haul my rig out of the water. It's much friendlier to split the load up between a couple of weight pouches and the backplate and tank.

 

[MikeFerrara]

Clear example of need to drop weight at surface:

Quote
The coroner at the inquest into the death of 41-year-old Paul Imeson, who died after a dive off Anglesey in October 2003, has concluded that he drowned on the surface.

Coroner Dewi Pritchard-Jones recorded a verdict of accidental death after hearing evidence about Imeson's death at the inquest in Llangefni, Wales.

The inquest heard that Imeson was an inexperienced diver, and had recently learned to dive on a three-day PADI course in the Caribbean. He was shore diving at Trearddur Bay with his brother-in-law, an experienced diver, and another inexperienced diver.

Imeson became distressed after surfacing in the swell and removing his mask and regulator. He appeared low in the water and was struggling to maintain sufficient buoyancy. The coroner found that he had inhaled water, passing out and drowning before his companions had recovered him onto rocks and begun attempts at resuscitation.

I've seen divers do this many many times although most don't die. They get spooked at reject the mask and reg (even though the reg is what enables them to breath) and don't inflate. Usually they'll inflate if you yell at them. If they don't you reach over and inflate for them.

Ditching weights would have kept the diver at the surface but so would inflating the bc. Keeping the reg would have prevented drowning whether the diver stayed at the surface or not. Of course if the divers tank was bone dry the diver would need to ditch weights if they were over weighted but note if the diver was negative with an empty tank that they ARE over weighted. All pretty typical of a new diver after such a short class.

 

[diverbrian]

You run into some issues that make things that make things somewhat different.

If someone has a problem with ditching lead to stay afloat think about this....

I am 5'9 to 5'10 depending who measures me. My weight is in the 180 lbs range (Yes, for me that means that the dunlop syndrome is starting. I will actually have to start watching what I eat). Now, I typically dive a rig of steel HP 100's doubled up with a steel backplate. The cost of the extra gas that I am carrying is that I am severely overweighted with no ditchable weight already. I am not ditching my whole rig at depth or on the surface unless it is an extremely dire situation. The positive point is that with that much gas, I have never been remotely close to running out of air. The negative is that if I come up, some DM can't simply drop my weights for me (I am assuming that I am out like a light or otherwise unable to do it.) to help them keep me afloat. So, I had better not need help diving that rig.

Ditching the victim's weights to ensure positive buoyancy is frankly one of the first things that potential rescue divers are taught to do with a panic victim as it is something that you can do for them relatively quickly and they may not have enough air for the power inflator to their BC to function.

And I was in a position a couple of weeks ago with someone who never admitted that they were that low on gas, but was inflating their BC by oral inflation when I mentioned to them that they should inflate their BC for the surface swim back. I noticed that they didn't drop weights, but why should they if they have positive buoyancy established with the BC?

Yes Mike, in an ideal world, nobody would be overweighted/underweighted and we would all dive perfectly horizontal, etc.... The problem is that (as an engineer you know this) there are differences (many times severe) between the ideal concept of an idea and real world. Sometimes they need to be accounted for.

BTW, I can't think any agency that recommends ditching weight at depth for anything but a desparate situation. I know that ditching on the surface is considered an entirely different matter by any account that I have read.

 

[Mako Mark]

what about being able to ditch someone elses weights while underwater?

I figure that human beings float, so in the event of an emergency, the last thing you need is something that makes you negatively bouyant. ESPECIALLY AT THE SURFACE. drowning is caused by exhaustion and not being able to hold yourself at the surface.

 

[RiverRat]

what about being able to ditch someone elses weights while underwater?

I figure that human beings float, so in the event of an emergency, the last thing you need is something that makes you negatively bouyant. ESPECIALLY AT THE SURFACE. drowning is caused by exhaustion and not being able to hold yourself at the surface.

I'm currently taking a Rescue course and HIGHLY recommend it to anyone concerned about these scenarios. So far I've just done the pool dives but got to practice ditching other divers weights at the surface to ensure positive buoyancy.

You would probably not want to ditch another diver's weights underwater unless it was a last ditch effort to get them to the surface. If they are very overweighted you run the risk of an uncontrolled buoyant ascent and possible barotrauma to the person you are rescuing. You would first want to try to inflate their BC to counter their weight. Of course now you would have to control their BC and your BC on ascent. If they are weighted properly you could just use your BC, but if you let go of the diver (such as if he panicks and you have to push him away to save yourself) then A. - you now have to dump air so you yourself don't have an uncontrolled ascent, and B. - the person you are rescuing will now start to descend. 2 schools of thought but you have to make a snap decision on the fly as you never know what the situation may be in a real rescue. I'm still in training so take the course if you really want to learn this stuff. Invaluable in my mind.