DIR- GUE Balanced rig with a thick wetsuit - mathematically impossible?

[johndiver999]

Maybe it is overthinking and I too wonder what can possibly happen to the BC to cause total failure. However, I think the purpose of the example given in class is to get the student thinking about weighting and understanding the balanced rig concept. A lot of students are taking Fundamentals after taking OW or maybe AOW and weren't exposed to the information. I know I wasn't. However, what I did learn from AOW was that I wanted/needed more training and Fundamentals was my choice.

As to the example, it got me asking myself questions about weighting and what it means to dive a balanced rig considering the two extremes; 1: Divers should be able to hold a stop with nearly empty tanks and 2: Divers should be able to surface with a failed wing.

Below are some of the questions and observations I got out of the example. I bet the OP had some of the same observations based on the posting of the thread. If I am wrong let me know.

Is this a balanced rig? Why or why not? No. Although it meets extreme 1, being able to hold a stop with nearly empty tanks, it doesn't meet extreme 2, being able to surface with a failed wing. The diver is 22 pounds negative at 100 feet and the baseline weight that a diver can comfortably swim up to the surface is 10 pounds so the diver is overweight by 12 pounds for extreme 2.

Is this a balanced rig if the diver dropped the weight belt? Why or why not? No. If the diver dropped the 12 pound weight belt it brings them down to negative 10 pounds and they can comfortably surface so now extreme 2 is fulfilled; however, extreme 1 would not. At 10 feet the diver would be underweight by at least 6 pounds and maybe more depending on how much gas was used to ascend.

Is this a balanced rig if the diver had ditch-able weights equal to the weight of the gas in the tank? Why or why not? No. If the diver just ditched the weight of the gas they would be good to go for extreme 1 but would not fulfill extreme 2. The diver would drop 6 of the 12 pounds carried but would now be negative 16 pounds or 6 pounds over the 10 pound weight standard.

I realized that just doing a weight check at the end of a dive with an empty wing and near empty tanks may be insufficient since it doesn't take into consideration the beginning of the dive (extreme 2).

I learned from this thread options alternatives for a diver to surface with an unbalanced rig from old school shopping bags, better finning skills, DSMBs, bigger lung capacity, better fitness etc.

I realized why a drysuit would be preferred over a heavy wetsuit.

I realized that is impossible to balance the rig in the example. However, I think that was the intention so that I or any student would think about weighting in a wholistic manner. To really think about everything so one is properly weighted and not overweighted like many divers coming out of OW and AOW.

Maybe it is overthinking but I feel the example and the observations that come from it has made me a safer diver.

Now can we get back to talking about pee valves?

The simplest thing is to ditch some lead and do the hang deeper in a wetsuit.

 

[admikar]

No, the simplest thing is not to go in a wetsuit with a rig you can't swim up.

 

[rjack321]

No, the simplest thing is not to go in a wetsuit with a rig you can't swim up.

Not to mention that once you're at significant depth and in the coldest water its paper thin - offering the least insulation when you need it most.

 

[Angelo Farina]

Not to mention that once you're at significant depth and in the coldest water its paper thin - offering the least insulation when you need it most.

That is the good moment for pissing...
And you are warm again!

 

[admikar]

But only for a really short time!
And then you either flush like crazy before surfacing or you stink and beauties don't want to hang around you........wait, damn, maybe I should start flushing?

 

[Angelo Farina]

But only for a really short time!
And then you either flush like crazy before surfacing or you stink and beauties don't want to hang around you........wait, damn, maybe I should start flushing?

What you call "stinking" is the real smell of an old-style diver...
And my wife used to piss inside her 6.5mm wetsuit much more and frequently than me. Almost every 5 minutes, so she was warm back again...
She loved it, avoiding carefully to piss before the dive for having a bigger storage of warm liquid available...

 

[Celt]

I think a diver should be able to dive wet or dry. You don’t want to be cold in a wetsuit so buy MTM in a quality neoprene, it’s a fraction of the cost of a dry suit, some people really feel the cold and have to dive dry, personally I dive dry in the winter 5-6C and wet in the summer 15-16C. I’ve dived wet in a dry suit also.

 

[Eric Sedletzky]

Not to mention that once you're at significant depth and in the coldest water its paper thin - offering the least insulation when you need it most.

That depends on the quality and type of material.
There are dozens of different blends and densities of neoprene for different applications.

 

[Eric Sedletzky]

I think a diver should be able to dive wet or dry. You don’t want to be cold in a wetsuit so buy MTM in a quality neoprene, it’s a fraction of the cost of a dry suit, some people really feel the cold and have to dive dry, personally I dive dry in the winter 5-6C and wet in the summer 15-16C. I’ve dived wet in a dry suit also.

I want to know more about this MTM you speak of.
I used to dive dry and it became such a pain in the ass I went back to quality custom wetsuits for all my cold water diving.
I had suits made from Rubatex G231N neoprene, one was 1/2” thick for urchin diving, and I had a 1/4” thick one.
JMJ Custom Wetsuits I hear makes some great wetsuits.

 

[PfcAJ]

The spring can corrode and fail, the OPV cover can become loose and unscrewed and fall off, a zip tie on the corrugated hose can fail, The OPV valve base can crumble from aging and with no prior leakage or warning.

I've had a few failures myself, seem a few others and have probably eliminated many impending failures simply by checking the tightness of OPV valves.

Anything with the OPV isn’t a total failure. Just angle head up a touch and you’re gucci.

Top zip tie at the elbow would do you in. Bottom one at the inflator wouldn’t be a total fail as you can blow into the corrugated hose. Sucks but doable. Not really helpful if it happens near the surface or if you don’t have a hard bottom to land on though.