AlanS
New
Time to hold my hand up and admit I screwed up and ended up with mild case of Decompression Illness (DCI) on a recent dive liveaboard in the Maldives. There were however a couple of lessons to learn that may be of benefit to others.
I was with an experienced group of divers all who had 500+ dives and all but me (including the dive guide) were diving with EAN/Nitrox,The last bit is important as it makes you the limiting time factor on each dive with instructions such as 'keep an eye on your computer and let us know when you get to within a few minutes of no-deco'.
The incident happened during the third dive of the day after two earlier dives to 30m. With still 10mins showing my dive computer I spotted that my back up computer (that I take along more in case of a failure that to use during the dive) was flashing a warning and had switched into deco mode. I signalled to the guide/leader that time was up and did the usual safety stop. Ten minutes after surfacing I developed the telltale itchy skin rash which lasted for the rest of the day. .
Causes - As no one else was diving on air I was diving virtually to the no-deco limit on every dive .
I didn't do the deco stop as advised by the back-up computer so as not to appear like I couldn't read a computer even though I took the deco alarm on board (!).
I found that the the P-value on my main computer was set to P0 while the back-up was set to the more conservative P2.
Takeaways - Be very careful about repetitive diving in a mixed air group where you are the only air breather and there is no other check on the performance of your dive computer. Request that the dive guide/leader uses the same gas mix as the most restrictive person in the group (might get some blowback on that). If you have to be the 'tail end charlie' set the P value on your computer to the most conservative value and don't repetitively dive close to limits . If you have more than one computer decide on actions in the event of alarms etc before you get in the water. Get EAN/Nitrox qualified so you always have the option.
Safe Diving. Alan
I was with an experienced group of divers all who had 500+ dives and all but me (including the dive guide) were diving with EAN/Nitrox,The last bit is important as it makes you the limiting time factor on each dive with instructions such as 'keep an eye on your computer and let us know when you get to within a few minutes of no-deco'.
The incident happened during the third dive of the day after two earlier dives to 30m. With still 10mins showing my dive computer I spotted that my back up computer (that I take along more in case of a failure that to use during the dive) was flashing a warning and had switched into deco mode. I signalled to the guide/leader that time was up and did the usual safety stop. Ten minutes after surfacing I developed the telltale itchy skin rash which lasted for the rest of the day. .
Causes - As no one else was diving on air I was diving virtually to the no-deco limit on every dive .
I didn't do the deco stop as advised by the back-up computer so as not to appear like I couldn't read a computer even though I took the deco alarm on board (!).
I found that the the P-value on my main computer was set to P0 while the back-up was set to the more conservative P2.
Takeaways - Be very careful about repetitive diving in a mixed air group where you are the only air breather and there is no other check on the performance of your dive computer. Request that the dive guide/leader uses the same gas mix as the most restrictive person in the group (might get some blowback on that). If you have to be the 'tail end charlie' set the P value on your computer to the most conservative value and don't repetitively dive close to limits . If you have more than one computer decide on actions in the event of alarms etc before you get in the water. Get EAN/Nitrox qualified so you always have the option.
Safe Diving. Alan
