The following is reported to have occurred in Sydney, Australia in early
August. One might say that Barry should buy a lottery ticket after this
one.
What a weekend! In Sydney to start my trimix course with Barry Hallett
at Southern Cross, Saturday was dead flat so bugger the course we did two
48m dives with a fairly hefty surface interval, 20m viz on the Coollooli
and the Dee Why.
Did some theory and mixing that afternoon, then
Sunday did another 48m dive on the wreck next to the Dee Why (Meggol), on
21.5/22 Trimix, I had a lovely dive.
Barry on his Buddy Inspiration fully
closed circuit rebreather however had a less than happy day (See below for
the full details). At almost 50m, Barry's 'breather gave him pure O2, yup,
6.0 atm, needless to say he suffered major nausea, visual disturbances,
and what he describes as like being hit with 240v, twice. He suffered two
big hits but was able to make it to the surface on open circuit, negating
almost 30min of deco, no signs or symptons experienced - he's a very
lucky man.
Not to be outdone, his other instructor, Kosta, also on a Buddy
Inspiration surfaced after a normal dive and deco, and took a mild
shoulder hit of DCS, so he went down for another 20min of deco, surfaced with
no other problems.
This is also after their new girl in the shop took a foot
hit on Wed after a 48m dive, normal profile with the only contributing
factor being she had cold feet - she's now going to buy a drysuit!
My dive went uneventfully, trimix is a lovely gas for clearing the head
and focussing clearly, and completing tasks much more quickly. Looking
forward to using it on the 70m dives next month, then......!
Barry's big day out: (don't read on if details bore you!)
Barry's Inspiration uses three separate electronically controlled O2
sensors and a polling method. Near the start of the dive and on the bottom
at nearly 50m, one sensor went u/s, and the computer asked him if he wanted
to recalibrate all three, and in his self admitted complacency, he answered
yes.
He later realised the computer was asking him a question akin to
"Do you want to suffer an enormous CNS O2 seizure and die, or not?" As
the O2 set point for the dive was 1.4, and as he had just told the sensors
that he was now only at 1 atm, and therefore PO2 of 0.21, the 'breather then
commenced adding pure o2 into the loop, with the expected results of
two major seizures.
He should not be alive to tell this story, as on the
ascent, having bailed to open circuit, his bailout gas supply exhausted
(he suspects it wasn't full to start with - error #2), luckily he had made
it to the ascent line and was able to receive gas from another diver, but
he continued to the surface fearing another major hit, which actually
occurred. He was also not cognitive of one divers efforts to give him
air, despite being right in his face.
Barry will freely admit he f___d up, due
to complacency. He still has faith in the rebreather, and is not shy
to tell people what he did wrong in order to let other people learn from
his mistakes. Here endeth the lesson.
Regards
From: Steven Bliim
To: techdiver@aquanaut.com
Date: Tuesday, August 31, 1999 11:40 PM
Subject: Rebreather problems?
Steven Bliim