Diving with No weights

[belairbrian]

been thinking through this and would like some input on it.

My daughter has been diving about 18 months (PADI JOW).
Up until now she has used an AL63 tank. i also have Compact 80s ( xs scuba steels) which weigh the same empty (27.7 lbs) but have very different buoyancy specs.

AL63 -3.0 to +.5
Steel 80 -9.0 to .3.0
(Both are full to 500 psi ratings)

So I'm thinking about moving her to one of the steels. The concern is this will likely put her at or below 4 pounds ditchable weight. Thus early in a dive she could be close to a point of not being capable of obtaining positive buoyancy if she had a BCD rupture. Since I don't know for sure, I plan to get her in the pool and weight her and see where she would be.

Obviously being negative at the surface with 0 ditchable (BCD deflated) would not be desirable. But what is the minimum weighting you would be comfortable with at the surface to offset compression of a 5/3 mil wetsuit at 35 ft?

 

[chrpai]

The whole "can you swim it up" point has been discussed over and over. My kids aren't old enough to dive yet and I don't know the age and physical / mental strenth of your kid.

If you think her skills are solid, talk to her about it. You have to test that she can wear that 5mm and "swim it up" from that depth of 35' with no air in the BCD and be able to swim it at the surface while it's negative or ditch it.

Is the 63 just not enough air for her? Does she need the extra gas to do the dives your doing?

If you forced me into a yes/no answer with what information I have I'd say don't do it.

 

[rx7diver]

been thinking through this and would like some input on it.

My daughter has been diving about 18 months (PADI JOW).
Up until now she has used an AL63 tank. i also have Compact 80s ( xs scuba steels) which weigh the same empty (27.7 lbs) but have very different buoyancy specs. ... So I'm thinking about moving her to one of the steels. The concern is this will likely put her at or below 4 pounds ditchable weight. Thus early in a dive she could be close to a point of not being capable of obtaining positive buoyancy if she had a BCD rupture. Since I don't know for sure, I plan to get her in the pool and weight her and see where she would be.

Belairbrian,

IMHO, being able to establish positive buoyancy at the surface with a full cylinder and an empty BC by simply dropping a weight belt is absolutely *essential* for rec divers. This is what I learned when I was doing my open water training. It made sense then. And it makes sense now. And this is what I am teaching my own young children.

You didn't mention the age, height, or weight of your daughter. An Al 63 carries a significant amount of gas even for some smaller adults.

FWIW.

Safe Diving,

rx7diver

 

[Milsimdiver]

Belairbrian,

IMHO, being able to establish positive buoyancy at the surface with a full cylinder and an empty BC by simply dropping a weight belt is absolutely *essential* for rec divers. This is what I learned when I was doing my open water training. It made sense then. And it makes sense now. And this is what I am teaching my own young children.

You didn't mention the age, height, or weight of your daughter. An Al 63 carries a significant amount of gas even for some smaller adults.

FWIW.

Safe Diving,

rx7diver

I have considered a steel 100 for the extra capacity but for the reason stated above I am more inclined to stay with an AL 80. I have heard this more then once about steel tanks.

 

[rx7diver]

I have considered a steel 100 for the extra capacity but for the reason stated above I am more inclined to stay with an AL 80. I have heard this more then once about steel tanks.

Milsimdiver,

I believe you'll find that a significant number of outspoken SB members will differ with my opinion ("Being able to establish positive buoyancy at the surface with a full cylinder and an empty BC by simply dropping a weight belt is absolutely *essential* for rec divers"). However, many others hold the same opinion.

I have dove both PST HP 80's and PST HP 100's--first wet (full 1/4" Farmer John, hood, boots, and 3-finger mitts) and then dry. Loved these tanks when rec diving in these exposure suits in fresh water! The wet suit provided enough positive buoyancy that I could establish positive buoyancy at the surface with a full cylinder with an empty BC by simply dropping my weight belt. And the dry suit provided sufficient *redundant* buoyancy--i.e., I could establish positive buoyancy at the surface if my BCD could not hold gas *or* if my dry suit could not hold gas (but *not* both).

However, I would not dive my HP 100 in my thin O'neil 3-2 wet suit in fresh water. And when I do dive my HP 80 in my 3-2, I never forget just how negatively buoyant this "little" cylinder is, and, so, I never dive it deeper than moderate depths.

IMHO, a rec diver has to be able to establish positive buoyancy, etc., *and* has to be able to swim a full cylinder up from depth (where his/her wet suit has lost a lot of its buoyancy) with a failed BC.

Of course, it is absolutely essential that a rec diver practices releasing his/her weight belt, over and over again. IMHO this practice should be done at the surface where it's safest: Remove the weight belt (don't drop it!), "show" the weight belt, replace the weight belt. Practice this often, as often as you practice air sharing and buddy breathing. Once every dive is not too often, IMHO.

Safe Diving,

rx7diver

 

[Dirty-Dog]

When I use a dive skin and HP120 I carry zero weight. But I also know that I can swim it up if I need to. I also know that my DSMB has 30lbs of lift...

In an ideal world, you might always have some ditchable weight. But personally, I'm not willing to give up the extra air (when I can get it) of the HP120, given the above facts.

You know your daughter. Does she have the physical capability to swim it up? If she doesn't have the emotional maturity to deal with such an issue, then she probably shouldn't be diving at all.

 

[rx7diver]

Dirty-Dog,

I've heard rec divers say that (in the case of not enough ditch-able weight) they will ditch their scuba or deploy their DSMB or lift bag. I remain unconvinced. My intuition tells me it is simply unrealistic to believe that a rec diver can pull off either of these in the midst of an extremely dire situation. These skills are simply not practiced in extreme situations. (Or not practiced enough, if practiced at all. Not in *extreme* situations!) However, one can practice releasing his/her weight belt (at the surface!) at least once every dive if he so chooses! This can easily be made a part of his/her safety drill.

In addition, we should be concerned not only with self-rescue, but buddy rescue as well: It is much more realistic (IMHO) to believe that a rec diver will be able to release a buddy's weight belt (at the surface or below) than ... what?

Safe Diving,

rx7diver

 

[Dirty-Dog]

Dirty-Dog,

I've heard rec divers say that (in the case of not enough ditch-able weight) they will ditch their scuba or deploy their DSMB or lift bag. I remain unconvinced. My intuition tells me it is simply unrealistic to believe that a rec diver can pull off either of these in the midst of an extremely dire situation. These skills are simply not practiced in extreme situations. (Or not practiced enough, if practiced at all. Not in *extreme* situations!) However, one can practice releasing his/her weight belt (at the surface!) at least once every dive if he so chooses! This can easily be made a part of his/her safety drill.

In addition, we should be concerned not only with self-rescue, but buddy rescue as well: It is much more realistic (IMHO) to believe that a rec diver will be able to release a buddy's weight belt (at the surface or below) than ... what?

Safe Diving,

rx7diver

I was, as I thought I made clear, speaking specifically about myself. With a dive skin and an HP120 with 500PSI my weight check is spot on. I have zero difficulty swimming up a full one, so I can't really see any reason to consider ditching it before I'm at the surface. I shoot my DSMB on most of our dives, so I don't think practicing is too big an issue. And since my buddy feels the cold far more than I do, she DOES have ditchable weight. So if my BC totally fails, and I am unable to either swim (did a shark rip off my legs?) or deploy my DSMB (and my arms?) she can bring me up easily.

I suppose that if both BCs and all 4 regs had total failures at the same time, we might have a problem. Well, and if nobody else from our group was able to help... I think you'll agree that's not a circumstance that we really need to worry about.

What is important is being able to get to, and stay at, the surface. If you can do that without ditchable weight, then fine. If not, then I would agree that you need to rethink your situation.

In general, I don't find intuition, especially as it pertains to juding the situation of a complete stranger over the internet, to be terribly convincing.

 

[belairbrian]

interesting comments about practicing dropping weights. With most rec divers using integrated weights and many using rental gear it makes you wonder how many could actually ditch the weight.

We were doing confined water class today. One diver (an 11 year old boy) could not pull the releases on his weight pouches.

We go through this while setting weights. Another was pulling out instead of forward and with way too little force. After being shown the proper way she was able to do it.

My issue with the 63's is two fold. They are older tanks and some places refuse to fill regardless of they alloy. Second is the cost of maintaining them, it's nearly $50 a tank just for the annual visual. Hydro is around $85 with the visual and fill added in.

 

[Ayisha]

...You didn't mention the age, height, or weight of your daughter. An Al 63 carries a significant amount of gas even for some smaller adults.

Yes, that is true. I am a petite female and I routinely use an AL 63. Even for deep dives almost to the NDL's, I come back with my tank about half-full. I know other women, even average to larger size, who also use AL 63's very successfully.

I have used a HP steel 80 occasionally and used only 4 lbs in fresh water with a 2 piece 7mm wetsuit, hood, neoprene socks, boots, and gloves. Normally with the AL 63 and the same exposure protection, I wear 16 lbs.

Off Catalina Island in salt water with the same gear and HP steel 80, I used 10 lbs.

In warm salt water with a HP steel 80 and a 3mm full wetsuit, I've used 2 lbs.

BelairBrian, I don't know what kind of build your daughter has, but as long as she's not overweighted, that's the main thing. We don't know how much weight she wears now.

How is your daughter's air consumption? Is she good on air or is she whipping through her AL 63? Can she try techniques to improve air consumption and relaxation and fine tune typical culprits like over-weighting and lack of streamlining first before moving to a larger tank?