Posted by MHK on January 15, 2001 at 16:13:35:
In Reply to: DIR on the West Coast posted by seahunt on January 15, 2001 at 13:16:11:
Seahunt,
I appreciate that you delayed the conclusion to your analysis until my return, whether intended or not ;-)...
As I noted in my GUE cave 2 trip report, I received an advance copy of the DIR manual and I hope it resolves many of your concerns, but in the interim I'll see what I can do..
You ask * What does it offer* and I'd respond by saying that it offers a comprehensive package that caters to the needs of both technical diver's and recreational diver's alike. To that end the DIR system when taken as a whole provides ample flexibilty to adapt to all diving environments. We have spent a fair amount of time discussing the DIR application as it relates to technical diving, and from my understanding of the exchanges it seems that we all agree that DIR is completely applicable to technical diving.. So the question that remains to be proven is this same system, when taken as a whole, applicable to the average Joe doing a fairly easy 60' recreational dive within our waters. Obviously, as you may expect I would answer yes, but I'll note my reasons inasmuch as a simple opinion doesn't warrant sufficient evidence amongst this crowd ;-)..
I've offered the analogy, to which I note that you still hold some suspicion that what is it I need at 400' that you don't at 60', so I'll approach this from a different angle. I hope to incorporate the application to the California environment but if you still find my response lacking let me know and I'll see if I can expand the analysis..
I'll add the following disclaimer and then proceed, my comments relate to the DIR system taken as a whole and my comments need to be taken in that regard, any parsing of the system, to which I hope by now is completely identified and understood, underminds the totality of the system thereby rendering it ineffective..
That being said, the genius of DIR system is that by it's very definition is applicable to any environment and given the countless number of dives that have been successfully completed in any environment with simple and relatively minor adjustements, I'll try line by line.
The reason for the inflexibility is that the system provides everything you need in the first place so by adding or omitting the carefully crafted balance is upset, and thus you distort the system.
To answer the direct question you pose respecting the need for a dive computer as a disqualifying factor to the DIR application to California.. I'll repeat what I have said on many, many ocassions. We hope that diver's will take the time to learn the various decompression theories therby rendering the reliance on a device useless.. In so doing you do a couple of things:
1) You eliminate the need to spend several hundred dollars on a device that could very easily be replaced with brain power. This is a further benefit when on a multi-day and/or live aboard, or even in the middle of your diving day and the computer either locks out, the batteries die, or it malfunctions, you posses the necessary understanding to rectify the situation. DIR is often accused of being cost prohibitive, but in actuality when you add the components and subtract the unecessary gear you'll be surprised how economical the system is:
2) To the extent that you do not have the necessary understanding of the models we say by all means use the computer until you gain the knowledge and capability. The primary objection in this regard is that you eliminate the cumbersome computer console and wrist mount the computer;
3) We futher eliminate the necessity for the computer with enhanced pre-dive planning. All too many diver's jump in the water and the only pre-dive planing is that I'll come up when my computer says it's time.. Different computers render different BT's and absent an understanding of the background you could have one diver surfacing wheil the other diver has an additional 10 minutes available.. In this case, the diver with the other computer has lost 10 minutes because of the lack of understanding.
4) I'm advised that some of the reluctance to eliminating the computer is that in the event you are forgefull and/or don't fully find yourself prepared to be without the computer you could cause an unintended DCS hit. In reality, we all keep a set of waterproof tables in our Wetnotes for this very reason.. Should this problen ever arise we'll take out our tables ( that cost about $10 ) and verify the NDL limits..
So the fear that I see is thruthfully without merit, however, as we have repeated often while it's preferable to dive without the computer, should there be a reluctance to do so we recommend that you simply wrist mount the computer..
I also see that you take issue with the recomendation that you only dive steel tanks when using a drysuit.. In my view this is a very sound principle for the following reasons:
1) Steel tanks remain negatively bouyant when empty.. Conversly Aluminum tanks while they start out negative when full swing to positive when empty..;
2) Should your primary inflation source fail ( ie; your bc ) it's possible that a diver will lack the wherewithal to surface absent an alternative inflation source ( ie; a drysuit );
3) If you are using a AL tank and your bc fails you'll simply gain the requisite bouyancy characterisitics as your tank swings from negatively bouyant to positively bouyant. In all honestly you are the first person to voice a material objection to this very sound principle;
Overall I'm confused by a few inconsistenies within your remarks.. I'm convinced by your cosmoligy that one of your objections to the DIR system is it's refusal to adopt the solo diving practices, but yet one of your defenses with respect to the use of a console is so that * it is easier for the buddy to check air and nitrogen status of a buddy*.. This information is very easily communicated between buddies and certainly doesn't address the need for cumbersome equipment configurations that all too often get caught in the kelp, get entangled inside wrecks and can be very easily avoided by simply re-positioning the same equipment.. I firmly believe that you are overstating the problems respecting wrist mounting and the hunters.. I'm an avid hunter ( generally only lobster ) and I have NEVER experienced a situation wherein my wrist mounted depth gauge precluded me from hunting.. With a proper undertstanding and/or a proper demo of the positioning I'm confident you'll agree with my analysis..
I agree with your comments respecting scooters on the west coast, but I'd add the point that the positioning of the gear bears little, if any, relationship to where the gauges are mounted.. In advanced diving techniques ( ie; the use of DPV's ) the benefits of the placements are simply a byproduct of the founding principle of DIR as opposed to dictating the positioning. For example, DIR diver's generally hold the light in the left hand and then wrist mount the gauges on the right arm.. One could easily reverse the positioning but the benefit to the light in the left and the gauge on the right is so that you can simply shine the light on your right arm to reach the gauge, and should you happen to be scootering, you'll not need to take a hand off the scooter inasmuch as we generally ride the scooter with our right arm.. But as I said you could just as easily reverse the positioning when not scootering.
I would also add that in your analysis you correctly point to our streamlinning concerns respecting the computer but I'm not sure you fully appreciated our position with respect to the potential entanglement hazared.. Furthermore, you talk about *not being able to claim the high road because of our fondeness for doubles* and then juxtapose the console issue vis-a-vis the doubles... I'd add that doubles are back mounted when needed and/or used and as such are already behind the slip stream, whereas the computer console hangs in front of a diver ( or more appropriately hangs under a diver's stomach area ) which significantly increases the coefficent of drag, adds unecessary weight the HP hose and adds an unecessary entanglement hazard..
In concluding, I'd offer the following thoughts:
I hope these exchanges have given the every diver, the DIR proponent and the DIR opponent, cause to stop and take a look at there diving habits. If nothing else, I've received many e-mails from the very experienced to the newly certified that our exchanges have caused them to re-think their diving habits.. I thank you Seahunt, and others for their participation, to that end... Hopefully we'll have added some safety aspects to the sometimes complacent habits of divers. I've attempted to answer directly every question that you asked and my intention was to take your hint ;-) and not avoid a direct answer, if you still feel I'm avoided please follow up because I'm here to answer not avoid, and I believe my historical contributions speak to that issue.
And lastly, and most importantly, my sole goal here is to highlight the fact that while diving is an inherintely safe sport, the opportunity for complacency ( more so to the experienced diver ), poor skills, poor training, poor equipment configurations, and the like all serve to tilt the balance from a relatively safe sport to a perhaps deadly endeavour. We had a horrible year last year, and sadly this year isn't getting off to a bang, and this is one of the few sports that I see a reluctance to learn from the mistakes of others. All too often defensive posturing replaces a common sense analysis of accidents.. In skydiving, in moutain climbing, and any other sport wherein the assumption of risk lies substantially with the participant, accident analysis is a standard component and friends and adversaries alike seek to learn from the mistakes of others. The early cave diving community, while they didn't necessarily share the same viewpoint on the surface, recognized that ALL could benefit from the mutual efforts. Sheck Exely is renowned still today for his contributions in that regard. I hope that one day the California diving community will lay down the flame throwers and adopt the same approach.. Until that day arrives I'll stay around and continue to highlight what I see, and keep in mind it's only my opinion.....
Later