Drop the freaking weights!

[nimoh]

Maybe not the most appropriate place for this anecdote, but at least it's on topic.

I was on a dive boat a few years ago diving without a wetsuit and a steel back plate, and was balanced (i.e. could swim up, and could hold a safety stop with no gas in the wing). Another diver on the boat suggested that I take a weight belt with a few pounds on it just so that I would have something to ditch in case of an emergency!

 

[lamont]

Something that is still missed in this thread is that the first place most divers need to drop weights is at the surface before they ever go on a dive.

 

[phoenix31tt]

Maybe not the most appropriate place for this anecdote, but at least it's on topic.

I was on a dive boat a few years ago diving without a wetsuit and a steel back plate, and was balanced (i.e. could swim up, and could hold a safety stop with no gas in the wing). Another diver on the boat suggested that I take a weight belt with a few pounds on it just so that I would have something to ditch in case of an emergency!

this may be similar thinking to what somebody told me once... when i was diving 4lbs (i now dive 2lbs... and on my next few dives will be evaluating no lbs)... the person said i should get a thicker wetsuit so that i need more weight to sink and thus have more ditchable weight


@lamont i think somebody mentioned it earlier up..people are to overweighted to begin

 

[raftingtigger]

I agree. IMHO this due to 2 main reasons. 1) They are afraid of being too buoyant, so it is easy to error on the heavy side. 2) They swim in a head up/fin down trim. When moving forward with the fins below the center-of-gravity the force generated by the fins has a horizontal component (desired) and a vertical component (undesired). The vertical component is compensated for by being negatively buoyant. The greater the head up swimming position the more the diver will overweight themselves to keep from ascending while they swim. Of course when they stop actively swimming they will then start to sink.

I saw a great example of this while watching a mainstream diving agency's Nitrox training video. I found it difficult to pay attention to the Nitrox info because of the subtle, but significant, head up trim and consequent sinking every time the diver(s) stopped fining.

I'll post a vector diagram for the physics challenged readers when I can.

 

[raftingtigger]

vector diagram as promised. Hope the quality is good enough.

 

[swimmer_spe]

If Sh!+ hit the fan underwater and I could not ditch my weight, I would ditch the BCD with my weight and steel tanks and just breath out to the surface.

I would then ask a diver friend if they would mind tying a rope to it so I could drag it up and figure out what the hell happened.

My life is not worth the $5000+ I have spent on my gear. It is worth much, MUCH more.

 

[Bob DBF]

this may be similar thinking to what somebody told me once... when i was diving 4lbs (i now dive 2lbs... and on my next few dives will be evaluating no lbs)...

There is a point of no returns, where you are not able to hold a stop when you need to.

I check my weighting on the return from a dive at 15' and 500# with the different configurations I dive. Knowing what is perfect, I add 2# to this when diving in case I need to hold at less than 15' or less than 500# or both. There are other situations where I will add a little more as necessary for the conditions I'm diving.

The proper weight is not some magic number as small as you can possibly manage, its the amount you need to dive safely.



Bob
-------------------------------
A man's got to know his limitations.
Harry Callahan

 

[nimoh]

I agree. IMHO this due to 2 main reasons. 1) They are afraid of being too buoyant, so it is easy to error on the heavy side. 2) They swim in a head up/fin down trim. When moving forward with the fins below the center-of-gravity the force generated by the fins has a horizontal component (desired) and a vertical component (undesired). The vertical component is compensated for by being negatively buoyant. The greater the head up swimming position the more the diver will overweight themselves to keep from ascending while they swim. Of course when they stop actively swimming they will then start to sink.

I saw a great example of this while watching a mainstream diving agency's Nitrox training video. I found it difficult to pay attention to the Nitrox info because of the subtle, but significant, head up trim and consequent sinking every time the diver(s) stopped fining.

I'll post a vector diagram for the physics challenged readers when I can.

I agree, but will add that I think there are a lot of divers that don't know exactly how much weight they need, so they guess. If the guess errs on the buoyant side, they can't dive, but if it errs a little on the negative side, not usually a big deal, especially if it is ditchable. However, if it errs a lot on the negative side, it better be ditchable.

This is very apparent on many dive boats I have been on where divers are asking the DM how much weight they should use. On more that one occasion, I have also heard DMs say something to the effect of "you should probably have 10 or 12 pounds, lets make it 14 to be safe".

 

[freewillie]

I will apologize for not having the time to read through all the posts. But, the initial assumption for some accidents is that the diver has a conscious choice about how to handle an emergency situation. After mentally weighing all options it may seem like a reasonable practice to then ditch the weights. And, for sake of staying within the thread, in the grand scheme of what we can pay for scuba gear (Atomic T3 anyone?) the cost of lead is relatively cheap.

Statistically speaking almost 1/3rd of scuba fatalities are primary medical issues regarding the diver's health for diver's over 50 and not necessarily from a diving "mistake" leading to a dive accident. For heart attacks in particular the diver would suffer a sudden change in health during a dive and may not have had time to ditch their weights. The diver may start to experience symptoms during the dive, surface, but then lose consciousness before establishing buoyancy at the surface then sink below the water with their weights. Or, they may simply pass out underwater before they have chance to ditch the weights.

Not all divers found underwater had a chance to drop their weights.

 

[phoenix31tt]

There is a point of no returns, where you are not able to hold a stop when you need to.

I check my weighting on the return from a dive at 15' and 500# with the different configurations I dive. Knowing what is perfect, I add 2# to this when diving in case I need to hold at less than 15' or less than 500# or both. There are other situations where I will add a little more as necessary for the conditions I'm diving.

The proper weight is not some magic number as small as you can possibly manage, its the amount you need to dive safely.

yup.. i'm following that same procedure, my last weight check was at 15' with about 300psi (i wanted to do an extended safety stop after a deep dive)... I held the stop with no issues and an empty wing with 2lbs... i have no problem with 2lbs just want to make sure it's not unnecessary