Dody
Contributor
One of my friends, a diver with about 100 dives over 5 years called me today saying that he had been in deco for the first time in his life but the circumstances are strange. He told me that he dived at 39 m and surfaced when the NDL was at 2 minutes. He said that after a while, the NDL rose to 3 minutes. He also claimed that his computer never gave any alarm. At some time, he got a serious buoyancy problem and told me that releasing air from LPI or valves did not work but this is not what triggered the deco, right.
We checked together and he rose from 24m to 4 meters in 2 minutes so the rapid ascent was not that severe. To make a long story short, he was not alerted of any deco, he did not know he was in deco, he did not do any deco stop, continued his dive and made a safety stop at the end. After the dive, he was shocked to see deco dive in the DC log although the computer is not locked. To add to the puzzle even though he did not do a deco stop, it seems that the deco disappeared a few minutes before the end of the dive (see attached pictures). What has happened?
We checked together and he rose from 24m to 4 meters in 2 minutes so the rapid ascent was not that severe. To make a long story short, he was not alerted of any deco, he did not know he was in deco, he did not do any deco stop, continued his dive and made a safety stop at the end. After the dive, he was shocked to see deco dive in the DC log although the computer is not locked. To add to the puzzle even though he did not do a deco stop, it seems that the deco disappeared a few minutes before the end of the dive (see attached pictures). What has happened?