double 104's

[ReeseTD]

This might be the wrong place to ask this question but since we are already talking about buoyancy of wet suits. Is there any graph or way to find out what a wet suit starting and at depth buoyancy is. I know that every wet suit will be diffent but is there a rule of thum that for every 1mm a suit is thy have X + buoyancy and at 100 thy will have Y + buoyancy?
Well i hope that was clear enoght to get some good responces and please forgive i suck at spelling

 

[Don Burke]

ReeseTD once bubbled... This might be the wrong place to ask this question but since we are already talking about buoyancy of wet suits. Is there any graph or way to find out what a wet suit starting and at depth buoyancy is. I know that every wet suit will be diffent but is there a rule of thum that for every 1mm a suit is thy have X + buoyancy and at 100 thy will have Y + buoyancy?
Well i hope that was clear enoght to get some good responces and please forgive i suck at spelling

I took my normal wetsuit exposure protection, a mesh bag, and some weights one day and came up with some raw data for various depths.

After I was done number-crunching, the figures showed that the buoyancy didn't exactly follow the reciprocal of absolute pressure, but followed a curve about one pound more buoyant.

There are different types of neoprene and not all of them act this way. Rubatex, for instance, isn't very buoyant and doesn't change much at all.

Your mileage may vary.

 

[Don Burke]

Karl_in_Calif once bubbled...
A single with a stage backup works great. Your back tank can be steel. Your stage is aluminum. You avoid the non-ditchable weight issue of twin steel tanks.

If you like EAN32 or EAN36, a 100 cu ft tank works fine. Even a 120 cu ft single will have less negative buoyancy than twin steel would.

The stage gives you redundancy during your ascent. You plan your whole dive including the egression and safety stops with your back gas, then you carry a stage with enough gas to substitute during the egression and safety stops. You sling this tanks for easy access, and keep it turned off until you need it.

If you load EAN32 into your back tank, you can load EAN36 into your stage tank, for more efficient off-gassing of N2.

A single tank with a stage backup gives you lots of flexibility, which you do not have with twin steel tanks alone.

This reads strangely like a TDI manual I read once. I didn't like it then, and I wouldn't dream of doing it now.

I note you didn't do any of the figuring.

You're trolling again, Karl, welcome to my ignore list.

 

[Boogie711]

And I know I'm not the only one.

I think he may be close to setting the record for the most hated poster in less than a month, or something like that. The little boy lives only to cause trouble, be obnoxious and stir up crap. Life is a lot nicer when all you see is a bunch of "This person is ignored" on your screen.

 

[Don Burke]

Boogie711 once bubbled... And I know I'm not the only one.

I think he may be close to setting the record for the most hated poster in less than a month, or something like that. The little boy lives only to cause trouble, be obnoxious and stir up crap. Life is a lot nicer when all you see is a bunch of "This person is ignored" on your screen.

With that last post, I think I know what manuals he found.

The trouble is, he hasn't read them very closely.

I'm up to four on my ignore list now and I feel better already.

 

[FIXXERVI6]

>I'm intrigued by the "2lbs just in case". What good does >that weight do you?

Just in case I have to run the tank to 0, I know I won't go positive, running it to 500 and no lead is fine, less than 500 and no lead may not be.

It would be texas lake diving, and WV lake diving, and gulf diving, the plan would be EANx and 100 to 130 feet, I just said 104's for the heck of it, I'm leaning tword 95's as well.

As far as the ditchable weight, I'd be in trouble right now with my single, if I ditch my lbs and my wing blows, I'm still going to sink, granted, I COULD swim my 80 up if I had a failure.

so what do cave divers do that dive shallow caves but need the high volume? I have seen cave divers jump in with skin suites and double steel, granted, I'm no cave diver.

One possibility would be a dual bladder BCD that I was looking at.

 

[Don Burke]

DB>I'm intrigued by the "2lbs just in case".
DB> What good does that weight do you?

FIXXERVI6 once bubbled... Just in case I have to run the tank to 0, I know I won't go positive, running it to 500 and no lead is fine, less than 500 and no lead may not be.

That would work out to a little under a pound. When you consider that your first stage will stay with low tank pressure, but your second stage may not provide air below about 120 pounds, it's even less. Being that little bit light isn't a big deal when you really need to be headed up anyway.

FIXXERVI6 once bubbled... It would be texas lake diving, and WV lake diving, and gulf diving, the plan would be EANx and 100 to 130 feet, I just said 104's for the heck of it, I'm leaning tword 95's as well.

I'd go for the 80s. They are much cheaper and useful for a range of dives.

FIXXERVI6 once bubbled... As far as the ditchable weight, I'd be in trouble right now with my single, if I ditch my lbs and my wing blows, I'm still going to sink, granted, I COULD swim my 80 up if I had a failure.

Staying with the standard 80 is probably the best plan. That six pounds will take care of the gas in the tank plus a little. You can swim the rest up.

FIXXERVI6 once bubbled... so what do cave divers do that dive shallow caves but need the high volume? I have seen cave divers jump in with skin suites and double steel, granted, I'm no cave diver.

If it is a cave you can crawl out of following a line, being heavy isn't as much of a problem. One you can silt up that way would get to be a big problem. Some of those guys are betting their lives that their wing won't fail.

FIXXERVI6 once bubbled... One possibility would be a dual bladder BCD that I was looking at.

I've been told the dual bladder BCs have some problems. It hasn't been an issue for me since I don't need one. Perhaps the issues have been resolved.

FWIW, with my double 80s, steel backplate, and 5/3 wetsuit, I need ten pounds in fresh water, which is marginal. In saltwater, I add eight pounds, which gives me some safety margin.

I haven't figured out a safe way to do staged decompresion dives in the ocean with a wetsuit yet. Until then, deco diving is done in the drysuit.

Edited to unmangle the formatting.

 

[Karl_in_Calif]

FIXXERVI6 once bubbled...
[BIt would be texas lake diving, and WV lake diving, and gulf diving, the plan would be EANx and 100 to 130 feet, I just said 104's for the heck of it, I'm leaning tword 95's as well.

As far as the ditchable weight, I'd be in trouble right now with my single, if I ditch my lbs and my wing blows, I'm still going to sink, granted, I COULD swim my 80 up if I had a failure...

One possibility would be a dual bladder BCD that I was looking at. [/B]

104s was a bad guess, then, as would be twin Fabers. These tanks are very negatively non-buoyant.

First question should be: Why are you buying tanks?

Second question should be: What is the best sized tank?

Third question should be: What kind of tank?

If you want to become certified as a Florida cave diver (I do not know if Texas has divable caves), and you want to start accumulating cave gear, fine. That should probably start with a drysuit. A trilam shell, or compressed neoprene, or semi dry will all be better choices than a wetsuit. Some groups will insist on one kind of suit over the others.

Once you are diving dry, then any steel tank or twins is probably appropriate, as the second acquisition. Unless you drive your car to Florida, you will probably rent tanks in Florida, if you go there. No need to buy any tanks at all.

If you decide to stay local in Texas, then take a look at what the locals dive with. They probably do not dive with twin steel tanks and a wetsuit.

If you want to keep wearing your wetsuit, then you are talking about NDL diving.

102 ffw = 4 atas
4 atas x 0.75 cu ft / min x 20 mins on EAN32 = one single steel 72 is about as big a tank as you need.

LP80 or HP80 works just fine too. But there is definitely no need for twin steel anything, whether 72s, 80s, 100s, or 104s.

I personally do not see a problem with a single steel tank together with a wetsuit. But twin steelies and a wetsuit is a totally different matter.

 

[Karl_in_Calif]

If I reply-in-king to Burke's and Boogie's ad hominems, I will probably bring the wrath of NetDoc upon myself, which I truly do not want to do.

Suffice it to say that I am happy being on Burke's and Boogie's ignor list. And Boogie has been on mine for a long, long, long time. For the record.

 

[Dryglove]

But there is definitely no need for twin steel anything, whether 72s, 80s, 100s, or 104s.

Its called redundancy. Since when is redundancy a bad thing? There is nothing wrong with carrying some extra gas at the end of a dive even when diving within NDL. I would rather surface with a 1000psi in my double 72's than drown from lack of air cause an emergency came up with me or my buddy.

What happens when a hose bursts when diving your single tank and your same ocean buddy has wandered off. You better hope its a slow leak and you can make it to the surface before depleting your tank or blow and go heading to the surface.

I simply shut down the affected post on my 72's and make a nice controlled ascent.

And Boogie has been on mine for a long, long, long time. For the record.

Hmmmm....you registered this month. I guess thats a long, long, long time in dog years maybe.