drrich2
Contributor
What is the better approach? Trusting the computer or doing pre-dive planning?
A lot depends on what kind of diving you will be doing. The impression I've gotten from training materials and some online posts in the past is that the 'model' for recreational diving is a buddy pair embarking on a rather detailed planned dive of a site with underwater topography known to them. One with a fairly squarish profile, perhaps?
In the 'real world,' it seems like a great deal of diving in the southern U.S./Caribbean region rather follows this model:
1.) You go out on a hired dive boat.
2.) A guide leads the group around. Some dive op.s allow buddy pairs to head off and do their own thing, but most customers don't opt to do that.
3.) The customers aren't that familiar with the underwater topography, which will likely entail a multi-level dive. The guide will set the pace of a roughly 45 to 50 minute no-deco. dive. In some cases divers with plenty of left-over gas can mess around under the boat before they go up.
4.) Deco. is to be avoided like the plague.
5.) Many of the divers are vacation divers, and even the more avid divers mostly aren't GUE-trained or diving at that level. Most aren't knowledgable about handling deco. (I'm not, either).
Yes, I know some op.s don't provide free guide service, and some buddy pairs strike out on their own. I'm saying what I described is the majority practice for the greater region. My belief, anyway.
The very large majority of the time, 'riding the computer' works fine for the kind of diving they do. If it works well with a good margin of safety, then your GUE buddy's approach doesn't have much to improve on...for that kind of diving. He may well do some diving his way is superior for.
Since he just runs in gauge mode, I wonder...how reliable is his brain/focus, potentially in the context of narcosis at depth, in keeping accurate assessment of NDL, etc...? Maybe just fine, I'm not trained or practiced at that level.
And do we really want people who aren't trained and seasoned to a GUE Fundamentals level (or similar) trying to dive your friend's way, if they're not ready for it?