Wisdom of trusting one's dive computer?

[CAPTAIN SINBAD]

Please keep in mind this is the basic forum, so discussions about 200’ dives on mix and depth averaging should not be discussed here.
Depth averaging from info based on tables is not something that should be attempted by recreational divers. Every table I’ve ever seen was developed for square profiles except for the wheel which was a pain to use and never really took off (side point). I doubt the top scientists of the world who came up with the tables did not plan for people to start adjusting and averaging depths and times trying to outsmart something that has taken many years of research to get right and were never designed to be monkeyed with.
It would take a mathematical genius, a freak of nature, to even begin to come close to how accurately a computer can adjust NDL time every second of the dive at any given depth. Dive times at different depths are not all the same in regards to gas uptake therefore are never linear, and therefore a straight average for all the different depths during a dive doesn’t work.
For someone to think that they can mentally keep track if every minute of their dive at every depth and do the fine math during a dive on the fly equal to a computer is insane.

You are correct. Conventional tables are not meant to be used for averages. This is why UTD and GUE folks use average depth tables called Minimum Decompression Tables. These are used with staged ascents so there is back gas decompression model built into it.

 

[tursiops]

You are correct. Conventional tables are not meant to be used for averages. This is why UTD and GUE folks use average depth tables called Minimum Decompression Tables. These are used with staged ascents so there is back gas decompression model built into it.

So, discussion of using average depth seems perfectly appropriate in the Basic forum. [/sarcasm]

 

[CAPTAIN SINBAD]

So, discussion of using average depth seems perfectly appropriate in the Basic forum. [/sarcasm]

Yes because Recreational divers are trained to use depth averages in such agencies like GUE, UTD and ISE. The line between tech and rec is not what it is in more mainstream agencies so there is no “forbidden knowledge.”

 

[tursiops]

Yes because Recreational divers are trained to use depth averages in such agencies like GUE, UTD and ISE. The line between tech and rec is not what it is in more mainstream agencies so there is no “forbidden knowledge.”

"forbidden knowledge"? Where does that arise? Who said/uses that phrase?

 

[Eric Sedletzky]

So GUE, UTD, and ISE are now considered standard recreational OW enough to talk about built in ratio deco and depth averaging from a special set of tables in the Basic forum?
News to me.
Better let scubaboard know so they can change their TOS.

 

[lexvil]

A better question may be what’s the wisdom in NOT following your dive computer?

 

[Lorenzoid]

"forbidden knowledge"? Where does that arise? Who said/uses that phrase?

You missed AJ's wonderfully sardonic post above?

 

[tursiops]

You missed AJ's wonderfully sardonic post above?

He refuses to play by the rules of the Basic forum.

 

[CAPTAIN SINBAD]

So GUE, UTD, and ISE are now considered standard recreational OW enough to talk about built in ratio deco and depth averaging from a special set of tables in the Basic forum?
News to me.
Better let scubaboard know so they can change their TOS.

The line between recreational and technical is not as clearly agreed upon between agencies as we like to believe. Different agencies choose to draw this line differently, based on their own history and evolution. DIR agencies believed that all dives are decompression dives so terms like "No Decompression Limit" become politically incorrect. Instead they get replaced by "Min-Deco" (Minimum Decompression) VS Tech-1 Deco or Tech-2 Deco. This means that the guy or gal who is at the same level as a PADI Advanced Open Water in the DIR style of diving is trained to do back gas decompression stops all the way up to the top using the following table.

When depth averages are used, they are used in relation to this table and not the PADI table or the US Navy table which is a square profile one.

Now, why are we having this discussion in the basic section? Because it would be agency discrimination to tell divers from GUE, ISE and UTD that their method of diving to a depth of 80' ft is not to be discussed in the Basic section because rest of the diving community falsely equates it to tech and we need to maintain that false perception.

 

[Lorenzoid]

He refuses to play by the rules of the Basic forum.

So is the underlying question whether GUE/UTD's basic rec teachings should not be allowed under the same "basic" umbrella as PADI's, NAUI's, etc.?