AbyssalPlains
Contributor
Aluminum or steel tanks?
Best time to do the weight check
- Thread starter k374
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Aluminum or steel tanks?
dkktsunami
Contributor
You don't seem nearly as grumpy as Rick.
Bubbletrubble
Contributor
Rick's statement goes for a set of 2 steel HP130's (slightly under 10 lbs. of gas in each).
I don't think AL130s are in use within the diving community.
It doesn't make any difference. 260 ft3 of air weighs the same no matter what kind of tanks it's contained in.
GrumpyOldGuy
Contributor
That may be, but one of the purposes of the forum is to teach good diving practices to newer divers. Under-weighting on purpose is simply poor diving practice IMHO. Consider the implications of under-weighting at a dive site with lots of boat traffic. Besides, any air you save by not schlepping that extra 5 pounds on the dive will be lost while you are finning down at shallow depths. Be comfortable and safe at the end of the dive. Weight yourself appropriately.
BTW, I love your username.
First, under-weight and over-weight are very relative and subjective terms. What I think is just right, someone else may consider over or under. On scuba board, probably both at the same time.
The more objective goals are:
1) Can I hold my safety stop?
2) Can I control my ascent all the way to the surface?
3) In an emergency, can I duck down again to get under a boat?
I can achieve all of these presently with ease, so I think I am good.
I am not trying to save air by watching my weight. My SAC is good (<.33) for a big guy. It more the question not wanting to deal with more lead topside than needed in cold water exposure suits and less fiddling with the BC down below.
Bubbletrubble
Contributor
With a SAC that good, if you're buddy diving, your buddy will probably be the limiting factor on your dive. If this is the case, chances are you'll be ending the dive with more gas in the tank than 500 psi. Having that extra ballast should make it easier to control your buoyancy at shallow depths, eh?
You seem to be well aware of the risks of over- and under-weighting. That's something.
Hopefully some newer divers have learned a little from this informative discussion. Stay safe out there...
scubadobadoo
Contributor
...when your pants no longer fit...
dkktsunami
Contributor
I have the same philosophy with this as you do. I currently use 19 lbs total with 7 mil and hood and have no problem holding horizontal stop at 10' or controlling ascent. I tried adding only 2 extra lbs. yesterday in local lake and was shocked at how clumsy this made me feel underwater. Can only imagine carrying an extra 5 lbs. for the rest of my diving career. I will add that most of my diving is warm water (60 deg. or more), al 80, non-deco, and rarely, if ever, surface with only 500 psi unless I have done so on purpose (vented gas for weight check).
Mathematically Rick M. has us bobbing to the surface and I can't argue with his logic. Nor do I wish to. I am only describing what works for me, and apparently you also. Maybe what you pointed out about delayed expansion of wet suit is the explanation, maybe being horizontal helps a bit, breath control helps a lot. None the less I have never had a problem with shooting to the surface. And I like the idea that I can spend several relaxed minutes at 10', feeling the up and down forces resulting from breathing, knowing that I have control of the situation rather than bobbing vertically on the surface wondering if my lungs are half full and trying to determine if water level is half way up my lenses.
I certainly would agree that this would not be appropriate for a newly certified diver (they are generally heavy anyway), especially on deeper dives with higher nitrogen loading and less gas remaining, and probably should be approached with baby steps and not the day after certification. For the type of diving that I do most often I am very comfortable with my weighting and always in control.
InTheDrink
Contributor
Dive site and dive conditions are also a factor. On a very shallow dive in surgy water I'll probably go for slightly more rather than less weight. For a deeper dive I'll try to get it smack bang on for an easy hold at 5m and a controlled swim to the top.
I think getting weighting right is a largely ignored aspect of diving *in the real world*. I've yet to come across a dive op that really spends much time facilitating it. I like one of earlier posts that suggests hanging back at the end of the first dive an removing or adding weight until correct until called in. That sounds like a solid real-world solution.
J
I think getting weighting right is a largely ignored aspect of diving *in the real world*. I've yet to come across a dive op that really spends much time facilitating it. I like one of earlier posts that suggests hanging back at the end of the first dive an removing or adding weight until correct until called in. That sounds like a solid real-world solution.
J
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