Actually no, that's not what I meant. But the tangent it sent you on was amusing.You mean I need to include DIR/GUE/UTD as part of the broader world of recreational diving?
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Actually no, that's not what I meant. But the tangent it sent you on was amusing.You mean I need to include DIR/GUE/UTD as part of the broader world of recreational diving?
I can't speak for anybody else, but I am not asking you to buy into anything DIR, Ratio Deco, or anything beyond school-level maths.You mean I need to include DIR/GUE/UTD as part of the broader world of recreational diving? Naw. They are outliers, a tiny fraction of the global diving activity.
My view of tables and actual depth comes from pre-computer days diving in Chicago, New England, Europe, using many kinds of tables. ALL of which clearly specify actual depth, not some sort of average depth.
One example above talked about going between 220 ft and 240 ft and calling it 230 ft. OK, that is what is called a tangent linear approximation, perfectly plausible for gas up take. But that is not the average depth of the dive, just of a little segment of it. That appears to be what the Ratio Deco folks have reinvented, the tangent-linear approximation. No magic, but definitely not the average depth of a dive, just of some segment of the dive.
The examples above that are trying to justify their position are really way off in the corner of recreational diving: trimix, 240 ft, 4h dives, O2 switch and deco, etc. Does the Navy dive manual or the NOAA diving manual or DCIEM or BSAC or anybody in the mainstream use average depth with a table?
This misses the point entirely. We are not talking about the averate bottom depth, but rather the average dive depth.it is not unreasonable to use the average bottom depth to calculate the NDL from a dive table
Can we get back to the topic of bungied wings, independent doubles, deep air or whatever the nominal topic was
For one agency, perhaps.Haha, except that the topic, gradient factors, ties in with average depth because GF Lo and the percentage used of average depth both determine the first stop of a dive.
So for some agencies, GF's and average depth are entwined.
For one agency, perhaps.
This misses the point entirely. We are not talking about the averate bottom depth, but rather the average dive depth.
Simple example using air, calculated on a PADI eRDPML.
100 ft, NDL, 20 mins, but ascend at 15 mins to 40 ft; new NDL is 83 minutes, but stay only 80 minutes. Nice 95-minute dive, plus some ascent time and a SS.
The average depth of that dive is 50 ft ((100x15 + 40x80) /95). A single dive to 50 ft has an NDL of 80 minutes.
You cannot validly plan or execute that two-level dive using average depth.
Names?Three!