I think he was going to bring up the whole "you cannot dive cold water without a BC" thing that comes up on here occassionally. Hopefully ZKY will pop his head in here.
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I think he was going to bring up the whole "you cannot dive cold water without a BC" thing that comes up on here occassionally. Hopefully ZKY will pop his head in here.
diver 85
Contributor
To the OP------good read............but that's life, it(life) is getting watered down more & more every turn we make...........
And most here have no idea what you're talking about....
And most here have no idea what you're talking about....
OP
Paladin
Contributor
Hmm. Divers were diving cold water for decades before the BC was even invented. It just goes back to proper weight control before you get in the water, not after. We learned from experience what amount of weight to use for the depth of the dive, regardless of the temperature. Yes, Virginia, you most certainly can dive cold water without a BC.
That's all I was asking about. Thanks.
I assume you weight for the end of the dive when your tank is lighter and do more in terms of swimming down to get to depth than would be done if you were "overweighted" at the beginning of the dive and used a BC to compensate until your tank was lighter at the end of the dive.
Is that the basic idea?
(edit: Actually, what I wrote doesn't make sense...so what is the process?)
OP
Paladin
Contributor
By George, I think he's got it!
But, yeah, being too light at the end of the dive can cause an uncontrolled ascent and that's bad news in anybody's book.
But, yeah, being too light at the end of the dive can cause an uncontrolled ascent and that's bad news in anybody's book.
The real trick is in the wetsuit. If you dive a Rubatex (or similar) wetsuit, it's so thick and dense that there is VERY little buoyancy swing at depth. This means that you can weight yourself (with no BC) to be a bit heavy with a full tank, then you'll be neutral by the time you breathe up your gas and you can still make your safety stop. You have to dive a weight belt (I always do) that way if all heck breaks loose when your tank is full (and hence the heaviest) you can ditch your weightbelt, or just swim your rig up from depth.
During the beginning of the dive, you breathe really full, to stay neutral. Towards the end, you breathe out fully, as to stay neutral.
Flotation at the surface with an AL80 or LP72 isn't an issue because an AL80 is postive at 500PSI and a LP72 is more or less neutrally buoyant at 500PSI. Those were the only two tanks made back then, and all that most vintage divers use (with few exceptions). Now would that work with a HP120, I don't know, I've never tried it. I don't know that I could do it, because my lung volume only allows me to account for about 5 pounds of buoyancy.
I hope I didn't confuse you
That is all good fun but it's not without it's compromises.
With a significant suit and weight for a predictable bottom you will first of all be working to get down. Forget about gentle descents on a shore dive. Of course you can carry a few rocks if any are handy. This effort puts you in a compromise position as an observant and reactive buddy.
Once down you can enjoy a nice dive with perfect weighting as long as your depth is fairly constant. Most divers can manage the buoyancy swing of an 80 CF cylinder with their lungs.
When it's time to come up that neoprene is going to rebound and you will be working to hold a stop. You're already breathing light to account for the air you used. Holding an anchor line is off base and again a shore dive won't be any fun at all. And remember to ascend at 30 FPM max now. Again there are things you can do such as gather rocks or have some lead waiting for the swim up but make sure you find them.
Most modern neoprene is softer and crushes more than the old stuff. This means you need to manage a wider buoyancy swing than in prior times.
Divers of the era you hearken to swam the dive. Mike Nelson didn't just hang there with perfect buoyancy very often, he was either driving forward or hanging on to something.
The advent of the BC was a curious period. The management of an air bladder was considered an advanced skill. The BC was created to enable advanced diving. Not as a crutch for beginners.
The kind of diving you speak of is good fun and in the right conditions I enjoy it. At the end of the day your sons will be in much better control using modern gear for most of their diving. BTW, I enjoy the vintage toys too.
Pete
NoVaScuba
Contributor
I think that's what pearldiver was getting was getting at. Professions, particularly ones that require a lot of training and ability, set the bar high to weed people out. Navy diving is a high professional level. The standards are different for recreation. You want to include as many as possible that can do it safely. They are then free to find their own difficulty/comfort level.
I think it's great that you set high standards for yourself. My standard is to know my limits and stay within those limits. If I find those limits constraining, I'll work to extend them.
Nova,
I like the way you think. I am all for diving being everyone's sport. Please do not think that just because I was military that I mean that everyone should go through the wringer. When in the classroom though, I do love to challenge people. I find that new divers really feel like divers when they feel like we didn't just "give them" their shiny new C card. You sound like you like to challenge yourself as well, but again, within your own limits. It's not like I'd make everyone swim 500 meters breast stroke just to pass OW.
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