Posted by MHK on April 11, 2001 at 12:28:13:
In Reply to: Re: Refreshed memory Repost again. posted by Steve on April 11, 2001 at 11:56:38:
Every dive profile is different and after re-reading your post I see that you meant in this particular profile. When I initially responded I read it to suggest that decoplanner itself didn't use 02..
Sorry for the misunderstanding..
Often times when we do a dive, or more accurately plan the dive, we are trying to balance several things. All of which can be explained in a GUE tech class ( hint hint).. ;-)
Seriously, 02 windows and pressure gradients and the proper gas is what we try to balance along with appropriate off gasing..
Our goal is that during an open ocean dive we don't want to be in the water longer than 90 minutes.. 90 minutes isn't an absolute for any other specifc reason that a lot can go wrong in the ocean ( ie; currents, fog, shipping lanes etc. etc. ) so we use 90 minutes..
A dive such as the Moody represnts an good comparisson for the way we approach a dive. Thanks to Pat for jumping in...
If you look at the way you appraoched and completed your dive and then compared it to ours I think any reasonable comparisson of the two would render a verdict that we do it safer and more efficently. That's not an indictment inasmuch as it is an observation that most out here that do the Moody see it as a *macho-type* dive and rather than view it as an opportunity to take a fresh look at an approach, it's gets jumped on as some type of benchmark..
I'm not fingering you in this regard since you and I have never met, but I've had this discussion about the Moody many, many times.
The local tragic history associated with the Moody is well known and doesn't warrant repeating.. And what we have clearly demonstrated in this thread, using a local dive, is that in fact our way is safer and more efficient..
Sadly, all too many have drawn battle lines in the sand, and rather than look at how we do things would prefer to call us zealots and steadfastly maintain that DIR doesn't apply to Calif. diving...
Discussions such as pressure gradients, 02 windows and the like have never been discussed locally until we raise the issue. It's a sad but true fact that many very experienced divers have no idea what this kind of stuff does and how it can effectively improve diving safety.. Rather than listen and ask, all too many want to say that we are a collection of cultists that standardize our gear and not much else..
We also have endless debate about how our way increases BT's and the desire to have an increased BT is often cited as the reason for using a ST tank.. Accordingly, we show a very effective way to spend 30 minutes on the bottom and be out of the water in under an hour and I believe this speaks volumes about our approach...
As to the 02 comment, we use it on many dives but in comparing the profiles in a 150' dive you don't save a tremedous amount of time by using 02 at 20' and then you would need to carry 2 deco bottles and frankly it's just unnecesary... Some do but it isn't required. Moreover, we have a team of safety divers that meets us at 70' they have an AL 40 with 50% in it and we have extra 02 at the 20' stop in the event of an emergency..
It always amazes me about a few of the guys on this list ( and I'm not including you in that crowd), but they babble on endlessly when the disucssion is theoretical in nature, but when we get into specifics and talk about issues they know nothing about all we hear is silence, but yet when it suits there needs they drivel on about the inapplicability of DIR to the local environment...
I often point to the story in the book The Last Dive wherein one of the local ( New York ) deep air cowboys got him and his father killed doing a deep air dive. The kid managed to live long enough to spend a few hours in the chamber and told his buddies that deep air was stupid, no one in that crowd listened and the deep air crap on the east continues... Aprope' to that story we have one of the guys on our team that can speak to a very sad experience on the Moody, ask him if he'll ever do the Moody again on air....
Learning from the mistakes of other's is an important element of diving, but yet all too many just want to argue and not listen..
Can the Moody be done on air???? Probably, I've done it many times... Should it given the advances in technology???? NO....
Later