CF55

[Bruce]

Hello,

Could someone please advise me of the correct function of CF55. As I read the custom functions list it seems to read like this-
Example, a simple dive GF 20/80 25min 42m with air and a 50% stage. CF55 set to 0. It asks for a 1min stop at 21m (hi-lighted in white). If I then set CF55 to 1 (now hi-lighted in yellow) to allow time for the gas change at 21m and it takes me 30secs to do the gas change and then tell the OSTC that this has been done. Does my 1min stop then now start giving me an actual stop at 21m of 1 and a half mins??

Bruce.
OSTC 2N 2241

[PeterK]

According to my understanding the value of CF55 is the calculation of TTS. With a number >0 your individual timing for gas switch is included in TTS calculation. It does not extend any calculated deco stop. Hope I did not misinterpret this whole thing.

[JeanDo]

CF55 include stops to switch gas in your runtime. In round minutes.

Example:
If you set CF55 to 3min, and you have deco gas with switch depth at 24m and 9m, then
you will have a 3min stop inserted at 24m and 9m (as soon as you dive below 24m and exceeded the no-deco-limit NDL time).

Of course, spending 3m extra time at 24m and 9m will change your gas loading/off-gasing. So the remaining of the runtime will be computed accordingly (usually shorter, but might be bigger is some situations).

This is the point: if you declare what you do (wait 3min to check every gas change), then the predicted runtime and TTS will better match you actual dive profile. --> See attached plot.

Cheers,