amobeus once bubbled...
In the case of a bladder failure at depth for example 240' they would use there dry suits to aid them to the surface while blowing a bag,
Correct. Let me try to assist you. Don't confuse weight on surface with buoyancy. Remember in the water at the beginning of the dive, My doubles are 16lbs negative, the stage is 9lbs negative, and the deco bottle is about 6 lbs negative, add the small amount of extras and total negative is about 30 to 35 lbs negative. The dry suit with underwear is about 20 to 28 lbs positive. What you have left over is 5 to 10 lbs negative at the start of the dive. Not as much weight as you would think. As the dive progresses you should start to swing closer to neutral at the surface. At depth all you need to do is add just enough air into your suit to make you around five pounds negative. Easy enough to swim up if needed. By shooting a bag you can remain slightly negative and pull yourself towards the surface.
If you are too negative after deploying a bag you can clip off the stage to the line and continue up the line. Or you can use the reel to wind yourself up.
Using a dry suit to get to the surface is the most unsafe method I have heard of and even if it was part of a training program I'd never attempt it. What happens if your suit burps or you swing, I can't see how this can be a safe method to use or teach while hanging at a deco stop with stage bottles and with all that weight wouldn't you be up to your waist in mud and --- out of luck.
Actually being neutral is being neutral it does not matter what you use for a buoyancy control device as long as you control it. by ascending very slowly you would be able to vent as needed. In fact while ascending from a decompression dive, stops every five to ten feet are common place which makes it very easy to control the suit. Remember that at the deco stops the gear is not heavy in fact towards the end they try to bring you up because they actually become more positively buoyant.
A back up bladder just seems to be the more logical method for me, isn't teck diving training mainly learning how to isolate and get back to the surface safely and alive.I haven't taken any teck courses yet but I figure this is the best place to get all my concerns and questions answered. I would like to hear from any one who may be able to help me understand some methods over other. I hope I'm not pissing any one. Amobeus
If you are not aware of the buoyancy of the gear in the water you are correct in the belief that a back up bladder should be required. If the tanks are correctly matched and balanced it really is not necessary because they really don't weigh that much in the water. By choosing the correct tanks for the dive you won't have the extra cost of a redundant bladder that you really shouldn't need even if the bladder completely failed.
I will leave with this to consider... if you rip your bladder or have a dump valve fail would it hold any air in a different position and still give lift?
No I'm not GUE trained, I hope this helps.
Hallmac
