It's relevant to PADI divers... who are taught to check weights using a pre-dive check. That description is an abbreviated reference to the technique they are taught. It could be more clear, but the reference doesn't describe the full technique or how to conduct it.
As mentioned several times in the thread - the debate is about safe diving practices that apply to you (your training). It's not about criticising the practices, standards and recommendations that don't apply to you...
Thal... how about sharing some insights from the scientific diving program?
From a Scientific Diving Safety Officer's perspective:
I fear that my insights do not support lists of "safe diving procedures." First of all there is the semantic question of the word "safe." Nothing in diving is safe, what we try to do is, "minimize risks." We spend a lot of time discussing and working through, in class, examples of how to identify and minimize risks using both Failure Mode Analysis and Probabilistic Risk Analysis approaches and techniques.
I do not like these sorts of lists, they are pre-chewed, pre-digested material with all the nutrition removed. Lists of the sort that were presented here, I would argue, are anathema to real diving risk management. Such lists are predicated on the idea that those whom I would define as Novice or Beginner divers are being put into the water unsupervised and that is something that, while commonplace in the recreational world, we simply do not do.
I can think of two areas where we have used such lists: Flying After Diving and Dive Computers. The Flying After Diving list is UHMS thing designed by lawsuit-shy physicians for Novice or Beginner divers that we never should have signed on to; and Dive Computer list (which I have to accept significant responsibility for) was a political piece of business that I spearheaded when I was much younger and had yet to define things, for myself, as clearly as I do today. Today my knee-jerk reaction would be to oppose it, but the politics of the moment (remember that back then most everyone except for a very small group of scientific diving administrators and very few manufacturers was opposed to dive computers) might have won me over in the end.
Thal,
As part of the weight check as taught in OW as well as other programs, the students are taught to add 4lbs if the weight check was done with a full tank.
Bill
Too late to edit my post now, so a new post just to clarify my last post. Specifics regarding the amount of weight to add is not mentioned, rather:
"Air consumption and the buoyancy check:
- During a dive, your tank will become more buoyant because the air you breathe from it has weight.
- Take this into consideration when conducting buoyancy checks at the beginning of a dive, when your tank is full.
- Depending on the tank you use, you may need to weight yourself slightly heavy at the beginning of a dive, so you’ll be neutrally buoyant at the end.
- Consider conducting a buoyancy check at the end of your dive as well."
That is the way it should be done, perhaps someone might suggest that PADI fix the list to reflect that?
