Posted by Chris on February 16, 2005 at 22:25:21:
In Reply to: Re: Another problem with computers posted by Brian Donaghy on February 16, 2005 at 18:37:49:
Brian,
It’s good to hear from you, but I’m afraid you are just wrong here.
It is just not practical to do on the fly depth averaging (which really means depth and time averaging) in many situations.
On some dives I do it would be no problem, but not for many of my hunting dives. Based on my nitrogen loading I set a depth limit on each hunting dive, but that is usually the only thing I know when the dive starts, especially if it is a spot I am unfamiliar with.
My goal on a hunting dive is to cover as much “good territory” as possible, this often involves swimming almost a mile during the dive. Good territory is defined ad that area in which lobster are, or have a high likelihood of being. Depths may vary up and down during the dive, directions I choose change, currents can vary, and I need to spend most of my attention scanning the terrain for hints of the prey. While I swim I constantly monitor my depth, the computers for remaining time at depth, the compass, and especially the air supply. When hunting your sense of time becomes distorted. It goes by slowly if you see no game, and fast if you find it. Thus it is the time distortion in combination task loading that makes depth averaging impossible and unsafe.
I understand computers screw up, that is why I always use at least two, and go by the limits of the one that is giving me the most conservative answer. You also need to have some awareness of your limits before you begin each dive.
To your quotes:
1) “I take quite a conservative approach and almost always come up with a very comparable NDL to most computer divers I may be diving with.” --- then why not just use the computer and spend more time paying attention to other aspects of your dive? As you said they work for non-decompression diving.
2) “ Once past their NDL 99% of dive computers produce absurd values” – I agree, but I am not talking about decompression diving here, and very few people who read this bbs are interested in deco diving. You are comparing apples and oranges here.
3) northcoast diver: “Can you not mark those who hand out dangerous advice with a little warning triangle or something?” – I believe people can judge what is BS for themselves, I don’t need to or have the time and desire to flag it for them.
I hope you make it back here to dive sometime and that we will meet when you do.
… Chris