I believe that some dives (overhead environments / ice diving) are more risky than others and that is the reason why most training agencies suggest ADDITIONAL training for these situations. I also believe that in addition to specialized training, specialized techniques and specialized tools of the trade are required.
Agree that additional training/experience is required. Having said that, the same contingency drills we use in non-overhead dives will also work under the ice -- I think this is a good thing. Making the jump to an ice dive is not that big of a deal for our team
Trying to have a "one shoe fits all" approach to diving, particularly in public safety diving, is dangerous, cumbersome and may not be in the best interests of taxpaying citizens we serve. If flexibility is not allowed, then the extreme is that ice shelters are carried to every dive site, even when it's not cold outside, we hang high lines on every operation, even when there isn't current, and we carry metal detectors on every dive since that is part of a "system" that is used when searching for evidence.
Agreed again. Thats why I believe in back up systems and choices as well. Just because we use a non-locking biner doesn't mean that we have less choices than a snap shackle - they are just a little bit different
If we can trust divers to use shears to cut their com rope when things go bad, can we not trust them to use quick release snap shackles???
Yeah. You're right. Either way the diver will be able to disconnect.
The differences (as I see them):
snap shackle - faster, more flexive with the tendancy to d/c earlier
biner - 1-2secs slower but is more deliberate, he may be inclined to attempt other options first -ie, the diver would really be thinking through the risk/benefits of d/c his line (I think this more thought out process is better but thats just me)
In two scenarios I mentioned earlier, one involving a former teammate and another involving Arthur Schumacher, the back up divers were on shore, standing by. In both scenarios neither a safety diver nor a redundant air source will save a diver in a Delta P scenario. When a diver's safety line is being pulled into a turning propeller, the redundant air supply and vigilant teammate offers little help. .
Agreed. I would hope that the team has the training to never get into that situation in the first place. A snap shackle doesn't ensure survival in this case either.
When I asked about back-up divers & redundant air I wasn't speaking specifically to your examples. Most of the time these will work but it depends on how they are used and if the procedures and skills are sound. Unless I was involved in an incident I'm very cautious to critique as its very rare to have all the info that you need to evaluate it. Its usually a cascade of effects that lead to trouble and its human nature to use hindsight and claim that "it would never happen to me because..." so I won't delve into it deeper.
I suspect too that there are some divers who should always be locked in with a carabiner and for those divers, a padlock may actually be more effective. Keeping them away from the water may likely be the best option!
haha! I've seen these guys too
Additionally, based on my experience and study, and based on the opinions of people whose opinions I value, I strongly believe that a quick release snap shackle offers an enhancement to the "safety" of public safety dive operations in most cases. Even PADI agrees!
As always, thanks Blades for your insights. I have come to understand that the snap shackle is not as bad as I had initially thought so I won't really argue against its use (as I used to). I don't believe it to be MORE safe than the biner (as you do) but I don't see it as dangerous either. There are certainly times, without question, when we cannot use the shackle (ice) and times when we cannot use the biner (strong current) I think agreement on these is most important.
Our team is still quite comfortable with our procedures as they are to maintain the use of the biner for the diving we do.
Good info