Question 40 or 50 lb wing for doubles? And what about (future) stage tanks?

[Imla]

Doubled old-school 72's (2 x 71.2 cu ft @ 2,475) + Luxfer Al 40 in salt water seem to work okay dove with a wetsuit. At least, the numbers suggest to me that this config will be safe enough.

rx7diver

Let me refrase that... "large double steels" (But usually the smaller steels will have too little volume for technical dives)
The problem is not so much the tanks OR the wing OR the wetsuit. The combination however is an issue.
The HP100s with a wetsuit is going to be a serious issue in case of wing failure. The size of the wing is then going to be a mute point.
A 40Lbs wing is perfectly adequate for D12 steels, if the diver is in a drysuit. D12 steels are not appropriate for technial dives in a wetsuit. (in my opinion of course...)

 

[rx7diver]

... But usually the smaller steels will have too little volume for technical dives ...

Hmmm. Plenty of technical dives are done using double Luxfer Al 80's (2 x 77.4 cu ft @ 3,000 psig). So, "pumped" old school 72's (2 x 86.3 cu ft @ 3,000 psig) should have enough capacity for some technical dives--not that I would ever recommend overfilling a 72.

rx7diver

 

[stuartv]

So... Is the problem in this story the wing, or the WETsuit? In which world is it a good idea to pair up steel tanks and thick wet suits? And should it not be your job as an instructor to guide your student before she is put in potiential harms way?

Yes, it is my job to educate my students. Here on the planet Earth, it is not uncommon at all for people to dive double steels while wearing a wetsuit. They do so safely using a variety of techniques.

If you would like training on diving in a wetsuit, feel free to DM me. I realize it may be a foreign concept for someone in Norway.

 

[Imla]

Yes, it is my job to educate my students. Here on the planet Earth, it is not uncommon at all for people to dive double steels while wearing a wetsuit. They do so safely using a variety of techniques.

If you would like training on diving in a wetsuit, feel free to DM me. I realize it may be a foreign concept for someone in Norway.

Personally... I religiously avoid wet suits. Water is EITHER warm enough for board shorts and rash-guard OR it is colder than bath water and hence warrants a dry suit.
However... I am still curious on how you would make diving a D12+ steel safe with a thick wet suit on technical dives. I can not get the math to work out in case of a wing failure.

 

[stuartv]

Personally... I religiously avoid wet suits. Water is EITHER warm enough for board shorts and rash-guard OR it is colder than bath water and hence warrants a dry suit.
However... I am still curious on how you would make diving a D12+ steel safe with a thick wet suit on technical dives. I can not get the math to work out in case of a wing failure.

What is "thick" to you?

I note that I did not say we were doing a technical dive. ('cause we were not)

In my Intro to Tech class, I educate my students on the need for redundant buoyancy, particularly when doing technical dives with double steels. I recommend a drysuit. I do note that using a dual bladder wing is an option that some people use. We discuss all the options, so that they can make good decisions for themselves when they progress on to taking actual technical training.

I don't like telling technical students "do it this way". I prefer to educate them on all their options. If I educate them well, they will make good decisions on their own. Of course, there are things during class that I will require to be done a certain way. But, where safety does not require a dictate, I let my students make their own decisions. Sometimes it is actually good to let them make, ummm, suboptimal decisions, so they can see for themselves the consequences in a controlled and safe environment. My Intro student from a couple of weeks ago is currently shopping for a drysuit - without me dictating it.