BCD failure at 100 feet

[GrumpyOldGuy]

For me it drives home how much divers today are dependent upon their equipment. Years ago we didn't have any means of positive buoyancy other than our fins or dropping our weight belt. We routinely did dives of 100 FSW or greater and had to kick like hell to get back to the surface.

We also had wetsuits that compressed less and loss less buoyancy with depth. They were more often custom fit because they did not stretch much either. The stock sized, super stretch, very comfy suites we buy off the rack now come with an increased reliance on technology (BCD). I did do some of my first dives sans BCD (just a Mae West), pain in the butt, 2 dives and I was ready to spend some money on a BCD.

 

[Teller]

Dual bladder wing.

Sent from my SPH-L710 using Tapatalk 2

Balanced Rig?

 

[Chilly_Dipper]

NOT True! With a thick suit at a depth of 100 feet, you will NEED to have a considerable amount of air in the Bc to be neutral.

Define thick suit.

I currently dive a tri-lam with heavy underwear but prior to this I dove a 7mm crushed neoprene drysuit and the combination of my lung capacity and maintaining a constant suit volume worked just fine with that as well.

The average set of lungs is ~6 litres so you can effectively shift your bouyancy by +-4.5 lbs by controlling your breathing which is more then enough to compensate for a crushed neoprene suit allowing for the extra weight you carry for the first 30'.

---------- Post added August 9th, 2013 at 12:02 PM ----------

PS. I also routinely dove a 7mm + 7mm wetsuit prior to the drysuits and have no problem swimming to the surface with an empty wing. If you can't swim off the bottom without the wing you're over weighted.

 

[GrumpyOldGuy]

Define thick suit.

I currently dive a tri-lam with heavy underwear but prior to this I dove a 7mm crushed neoprene drysuit and the combination of my lung capacity and maintaining a constant suit volume worked just fine with that as well.

The average set of lungs is ~6 litres so you can effectively shift your bouyancy by +-4.5 lbs by controlling your breathing which is more then enough to compensate for a crushed neoprene suit allowing for the extra weight you carry for the first 30'.

---------- Post added August 9th, 2013 at 12:02 PM ----------

PS. I also routinely dove a 7mm + 7mm wetsuit prior to the drysuits and have no problem swimming to the surface with an empty wing. If you can't swim off the bottom without the wing you're over weighted.

When you dive dry you have redundant buoyancy, so it does not matter.

The statement "if you can't swim up off the bottom your over weighted" is stupid! Grossly over simplified.

You are not diving a balanced rig and increasing your risk for sure, but you may be perfectly weighted. I depends on how much weight you need to suit compression and gas versus how strong a swimmer you are. That is highly variable day to day for the same diver. If you can't swim your rig up, then you better have a plan B to mitigate your risk. A dry suit or double wing is an excellent plan. A lift bag/smb is not ideal, but feasible. Dropping partial weight is also possible, but with its own added risk of fast ascent.

 

[danvolker]

When you dive dry you have redundant buoyancy, so it does not matter.

The statement "if you can't swim up off the bottom your over weighted" is stupid! Grossly over simplified.

You are not diving a balanced rig and increasing your risk for sure, but you may be perfectly weighted. I depends on how much weight you need to suit compression and gas versus how strong a swimmer you are. That is highly variable day to day for the same diver. If you can't swim your rig up, then you better have a plan B to mitigate your risk. A dry suit or double wing is an excellent plan. A lift bag/smb is not ideal, but feasible. Dropping partial weight is also possible, but with its own added risk of fast ascent.

To me, when the water temp and depth, force me to use a wetsuit that is so thick and buoyant, that I could not swim it up from depth with the tank and whatever integrated weight were part of my gear config.......then I would decide that either I had the wrong tank on( it is too heavy without buoyancy of the wetsuit) or the whole idea of using a wetsuit has become impossible at this depth and temp, and that you then must go to the dry suit....


We don't have this issue at all in South florida ( except divers using stupidly heavy tanks) , but if I lived in NY or NJ, and was wanting to do the Doria or similar, this would be a huge big deal.

 

[GrumpyOldGuy]

To me, when the water temp and depth, force me to use a wetsuit that is so thick and buoyant, that I could not swim it up from depth with the tank and whatever integrated weight were part of my gear config.......then I would decide that either I had the wrong tank on( it is too heavy without buoyancy of the wetsuit) or the whole idea of using a wetsuit has become impossible at this depth and temp, and that you then must go to the dry suit....


We don't have this issue at all in South florida ( except divers using stupidly heavy tanks) , but if I lived in NY or NJ, and was wanting to do the Doria or similar, this would be a huge big deal.

When I have dived West Palm Beach I actually technically overweight myself. I call it Viagra weight as I want enough at then end of the dive to keep my SMB erect as I fear being run over by a boat more than having to swim up with 12lbs of lead when drift diving.

The opposite happen in So Cal, diving off Catalina SMB's are not really needed (I still carry) as even if I loose track of the boat I swim to the edge of the kelp and ascend safely. In this case, being in 8/7 I use less lead than ideal because 30lbs is rough to swim up. The idea is that the suit crushes and does not recover completely at 15', so diving with less lead is OK, I just have to dive down the first 15' and make sure once I come up I don't need to duck for an idiot on a boat / jet ski.

Ideal weight is dependent on a lot of variables. There is no simple rule. That was my objection to the post.

 

[DCBC]

Balanced Rig?

Good Lord Teller, I just noticed that your NAUI number is just over 50,000 from mine. I must be getting old! LOL

 

[Chilly_Dipper]

When you dive dry you have redundant buoyancy, so it does not matter.

The statement "if you can't swim up off the bottom your over weighted" is stupid! Grossly over simplified.

If you say so.... we are all entitled to our opinions.

I will point out that most people that have trouble achieving neutral buoyancy are typically grossly over weighted. You see them all the time doing the roller coaster in the water column alternating between hammering air into their BCs and dumping like mad men. The ability to change depth with either an extended inhale or exhale is something I think every diver should aspire to regardless of whether they are in cold or warm water.

And as danvolker has pointed out if your in water cold enough to require a 'thicker' suit then a dry suit is almost required at that depth since a wetsuit at that depth offers minimal thermal protection.

 

[PfcAJ]

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The average set of lungs is ~6 litres so you can effectively shift your bouyancy by +-4.5 lbs by controlling your breathing which is more then enough to compensate for a crushed neoprene suit allowing for the extra weight you carry for the first 30'.

You don't have control of that entire 6l volume. There's a certain point where you can't exhale anymore, but your lungs aren't empty. And inhaling to the max is a great way to end up with co2 problems.

Balanced rig, as others have said, is the answer to this problem.

 

[GrumpyOldGuy]

If you say so.... we are all entitled to our opinions.

I will point out that most people that have trouble achieving neutral buoyancy are typically grossly over weighted. You see them all the time doing the roller coaster in the water column alternating between hammering air into their BCs and dumping like mad men. The ability to change depth with either an extended inhale or exhale is something I think every diver should aspire to regardless of whether they are in cold or warm water.

And as danvolker has pointed out if your in water cold enough to require a 'thicker' suit then a dry suit is almost required at that depth since a wetsuit at that depth offers minimal thermal protection.

Yup, opinions are like a-holes, we have at least one.

No argument about divers being over weighted and making life difficult for themselves. Being properly weighted however is judged by being neutral at your safety stop (15') with a near empty tank. You are making a statement that being properly weighted is judge by your ability to swim up from depth without your BCD. Those are 2 different subjects, both important concepts but different.