| 1.76 PPO2 anyone?
Not really a 'I learned from that', but a reinforcement 'this is why we teach this'.
On Thursday we had the go ahead that a trip out to the Chateaux Yquem was on. Saturday was binned due to forecast 4-5south westerlies. The wreck lies in 48m half way between Torbay and Portland. Sundays forecast was for 2-3 westerly. Could still be some swell though. As I didn't want to spend time around the bottom of the hull, I planned on a max depth of 45m
So Friday night sees me down the club sorting out my gas for the dive. The cylinders were still full of 32% from the aborted Sunday in Weymouth a couple of weeks before. So the plan was to drain down to 120 bar, then air top up for 26%. There were a few other cylinders needing filling, so all were connected up so the filling was slow and cool. There were a few other members wandering to and fro carrying stuff for a fundraising boot sale. The topping up was done and the cylinders put back in the car.
Sunday morning I was putting the rest of the stuff in the car. I though I would just check the mix. It measured just under 32%. Do what?! So I check the gauge and vent it and make sure it was resetting. Put it on again. Just under 32% again! Then it hit me. I had not actually done the draining down prior to topping up. What with the distractions around and connecting the other cylinders I had gone straight into 'fill mode'.
Luckily I had plenty of time to go back to the club, drain down and top up properly this time. The dive was not too bad, vis of 2-3m. Sea almost flat calm. Wave machine had been switched off. And another local wreck visited. Although I'll have to do it a few more times. Hopefully in better vis.
So, not only check your gas before you dive, but check the gas at a point where you can do something about it.
Adrian |