| Odd profile deco diving.
The thread on the VR3 started me on this!
My buddy and I do a dive here in Plymouth which is an odd profile and sorting out the dive plan deco schedule is not so easy. OK we have it sorted now but how do other people deal with odd profiles?
Here is the way it runs.
0-12m is a 5 minute dive (surface current makes surface swim out of the question) of fairly consistent slope.
12m to 25m is 3 minute dive, a gradually increasing slope.
25 to 35m is vertical wall, but due to strength of current takes 2 minutes to drop.
35m to 45m to 35m to 30m is the bottom so 15minutes spent on bottom.
Ascent is wall to 20m, slope to 12m (10 minute dive) , then long slow dive (30 minutes) in on a gentle slope to surface.
Gases used 21/35 and 50% deco gas. Gas switch at 21m.
Now we break this down into each segment and then run it through V-planner assuming 45 metre constant bottom (see always cautious). Apart from the ascent where we work on the basis that last 20m ascent over 40 minutes must be fine (or am I barking up the wrong tree?)
If you run a dive computer (well Tec2G) on this dive it hates the long slow ascent and penalises accordingly (so we hang around at 3m waiting for that to clear.)
If I run a 45m dive on the V-planner for 21/35 and 50%. it gives roughly the same dive time as the Tec2G on 21% and 50% (just a note as I like playing with figures).
Hope that is clear!
Martin
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