Importance of dumpable weight

[Texasguy]

Let us say that a diver is not carrying more weight than needed, that the buoyancy is right on the dot for that diver.

In what situation would dumping weights be a must for any diver (I would assume an emergency situation)?

If a diver is properly weighted, dumping weights, would it really make a difference in ascent speed or effort?

Have you ever needed to drop weights?

 

[mainedvr]

I have found and see why it is so that, first you should be able to swim your rig to the surface with out dumping weight (balanced rig). Then once on the surface, if you should need to dump weight you should only need to dump the amount of weight you used to make up for the air you would consume during your dive (the weight of that compressed air) say for instance 6lbs.

So realisticly you would only need to dump that much weight once on the surface to be postitiven and really if your neutral at 15' then you would more than likely be positive at the surface more or less anyhow, dropping the weight may make it easier for you to be towed on to the boat or back to shore and maybe other scenarios.

I am not sure if there would be a need or a want to dump weight during the accent as you should always make a controlled assent regardless.



I have never needed to drop weight other than around the middle....

 

[fdog]

As a generality, dumping weights is a terrible way to get to the surface. However it is a great way to stay at the surface.

Assuming you're correctly weighted.


All the best, James

 

[chrpai]

When you are properly weighted it's for at the surface with 500psi. At the beginning of the dive, and at depth (considering wetsuit compression ) you'll be negative. This is why you put air in your BCD... to get neutral.

So let's say your BCD fails and you are now negative. Some agencies teach to dump weight and get positive. Other agencies teach the balanced rig concept in asking the question "can you swim it up?"

My rig is probably about 10lbs negative at depth and as I swim it up it is less negative. Thus I have no ditchable weight.

Basically I've asked myself what is the greater risk? An accidental ditching of weight and resultant buoyant ascent or a negative buoyancy issue that requires me to swim it up.

 

[boulderjohn]

Of course ditching weight under water is n case of emergency. The problem is determining what level of emergency is needed to go to this extreme. IMO, it has to be a pretty bad situation to get me to that level. I would have to be in a situation in which I had to get to the surface in a hurry and did not have the physical capacity to do it through my own efforts. That would mean a lack of BCD inflation and a lack of my ability to kick effectively. It might also be a medical crisis that leads me to suspect there is a chance I might pass out.

Although I have clearly said it is a last chance situation, I understand that the fact that in a large number of diver fatalities, the divers are found on the bottom with their weights on. That seems so obviously wrong--why would the diver not drop weights in that emergency?--that I cannot help but think that the diver did indeed lose consciousness unexpectedly and was thus unable to ditch the weights.

 

[flots am]

Let us say that a diver is not carrying more weight than needed, that the buoyancy is right on the dot for that diver.

In what situation would dumping weights be a must for any diver (I would assume an emergency situation)?

You need to ditch weights whenever you are unsure of:

• Your ability to make it to the surface
• Your ability to stay there.

While needing to ditch your weights at depth means you've already screwed up a bunch of times on the same dive, it is more-or-less safe when diving within the no-deco limits, and is much safer than drowning.

Ditching your weights on the surface is an awesome idea if you're at all uncertain of being able to stay there, or even if you just want a little more "altitude". All the weights you're carrying probably cost less than the boat-ride you just bought and definitely less than a funeral.

If a diver is properly weighted, dumping weights, would it really make a difference in ascent speed or effort?

Absolutely. If you ditch 15Lbs of weights, you'll have an additional 15Lbs of upward thrust, which will probably send you up at much more than a safe ascent speed.

Have you ever needed to drop weights?

No, but I would in a heartbeat if I thought they were causing any problems. Weights are just "stuff" and you can always get more stuff.

flots.

 

[GrumpyOldGuy]

Some cold water wetsuit divers might have issues swimming up their rig from deep water with a total BCD failure (not a little leak, but ripped wide open, not typical). You have to be in really thick neoprene that compresses a lot (like some of the super stretch stuff) and deep enough were it is highly compressed (100+ feet) and be a bit heavy on the weight (+ full tanks). In this "perfect storm", which is a real long shot, a partial weight release would be nice. A better solution (assuming you have gas) is to shoot a good sized SMB and let it provide some extra lift without becoming a rocket to the surface.

 

[chrpai]

Some cold water wetsuit divers might have issues swimming up their rig from deep water with a total BCD failure (not a little leak, but ripped wide open, not typical). You have to be in really thick neoprene that compresses a lot (like some of the super stretch stuff) and deep enough were it is highly compressed (100+ feet) and be a bit heavy on the weight (+ full tanks). In this "perfect storm", which is a real long shot, a partial weight release would be nice. A better solution (assuming you have gas) is to shoot a good sized SMB and let it provide some extra lift without becoming a rocket to the surface.

They should dive dry then. Trust me, I know. I used to dive 2 pc 7mil in 38f water with an LP104 and 28lbs of lead in a jacket BCD. It was really stupid of me and I'll never do it again.

 

[GrumpyOldGuy]

They should dive dry then. Trust me, I know. I used to dive 2 pc 7mil in 38f water with an LP104 and 28lbs of lead in a jacket BCD. It was really stupid of me and I'll never do it again.

I have done 40F wet and your right, its not fun at all. I dive dry when its below 50F water or air temp or deep dives (100+). It is much more comfortable and the P valve is one of my favorite inventions.

Regardless, there are plenty of divers wearing 2pc FJ+jacket or the super thick jump suits in 50-55F water who are on the edge of not being able to swim up from deep water with no air in their BCD. It depends on how strong a swimmer you are (dare I say split vs paddle fins), how deep, how compressed your suit is, etc... Being able to do a partial dump is just another safety tool in the box you can use but probably never will need, next to you signal mirror, whistle, backup light, etc...

 

[chrpai]

Regardless, there are plenty of divers wearing 2pc FJ+jacket or the super thick jump suits in 50-55F water who are on the edge of not being able to swim up from deep water with no air in their BCD.

What concerns me about that ( well, not technically concerns as they aren't my buddy... ) is that they probably don't know if they can swim it up or not.

I didn't know.

When I retired from diving I gave everything away with the promise that if I ever got back into it I'd reconsider every piece of equipment, training and dogma that I had ever embraced or rejected. One of the results of that choice is a balanced rig that I know I can swim up. If I ever need more then a 3mil (probably this fall ) I'll drop the $ and go dry.