Incident Report

2001-06-06I had dived to 230m/-40m and was returning through a fairly low(40-50cm)bedding plane at 30m/-12m when I ground to a halt.I tried to free myself by moving backwardsforwards and sideways but remained caught on the roof.The cause of the problem was not obviousas I seemed to be caught somewhere between my shoulder blades which I could neither see nor reach.I therefore took off both my 7.7l cylindersbut remained caught so began taking off my harness.I had undonebut not removed it when I found I was no longer caught on the roof.Next I put back my gear and returned to the surfacedoing precautionary decompressionwhich took me just into the third 1/3 of both cylinders.Upon reflection I decided that a webbing strap and/or plastic buckle on my harness had jammed in a groove or between projections in the roof of the bedding plane.CDG training and 20 years experience do help.The Thirds Rule does work.I cannot identify any change of equipment or technique that would avoid a repeat of this (?unique) incident.A few days later another CDG diver completed exploration of a somewhat roomier bypass to the bedding plane.I have used this route on all subsequent dives at Ilam.