I was on a weekend dive trip last Saturday. Upon arrival, we had our first shore dive at 5m depth for 1 1/2 hour. Then we had 3 1/2 hours surface interval before we went for a wreck dive with 28m depth.
So, this was what happened. We descend through a buoy line and reached the wreck at 28. And we separated from the DM within a minute due to poor visibility (3m). 3 of us however, decided to continue diving with all our torches on. Saw some nudibraches and tunicates, and we did some shots(photography). Swimming around the wreck, looking at the Dive Com, the NDL says 5 mins and I suggested an ascent. So, we did.
Remembering the DM briefing about the Dive site was to have a deep stop and a safety stop. But couldn't remember what was the depth and stop duration. we ascent while looking at the dive comp, it now shows 5 mins, small deep stop and ceiling. So, I thought it was a deep stop. So, we waited a while and the 4 mins did not move where the Dive time has jumped a min or more. Feeling a little impatient, I told my buddies that we're ascending slowly anyway. So, we did.
While ascending, I realized the number increased and the first thing that came to my mind was, "Why is the number increasing. Is it because we didn't stop enough and we have to stop longer now..?" Didn't care much and we continue ascending.
When we reached the depth about 20m, Suddenly logic and rationale came back. I looked at the dive com again and now it shows even more time. Then I realized i made a mistake and I signaled to my buddies that we're ascending to 14m for deep stop.
Back home on Sunday. While logging my dives on Monday, filling up the details and pressure group of that particular dive, I realized that if you start a dive with Group A, the maximum bottom time we have for 28m is only 20mins. And the dive profile of that dive indicates we were at 28m for 20mins.
I think it was narcotic effect that have causes my response to slow down and poor ability to analyze. How could I mistaken NDL with Deep stop.
