26 February 2007

[insert generic title here.]

It's not that I don't want to write, it's just that every time I sit down to write, I get all blocked and my mind becomes completely blank. So perhaps just quick updates here and there, until I'm feeling back up to blogger snuff.

I'm finally feeling healthy again, and am no longer sleeping all my days away. Classes continue to go well. Last Tuesday was the last in-pool session for the scuba techniques class, and amazingly, I successfully completed the skin diving ditch and recovery. I do think the instructor was being kindly in passing me, because I've heard stories from those who've failed the exercise, and my attempt was actually a bit shoddy in comparison. But, I shan't argue, as I'll walk away with an A. For the same class, Saturday was our first day in open water at Leadbetter Beach, just a stone's throw from the college. We worked on free diving, configuring equipment, determining weight, and demonstrated some basic skills underwater. Towards the end of class time, the instructors cut us loose to dive on our own, with a buddy. Due to a receding tide and swell and surge, visibility was about 6 inches or so. At one point, I completely lost sight of my buddy Dave, truly and honestly could neither see him nor distinguish the outline of his body, when he was no more than 2 feet away from me. I ended up holding on to part of his kit for most of the dive. Fortunately, for the remaining 2 classes we'll be diving from a boat, which should make for far lovelier conditions.

Friday was the first day (of 2) of a Nitrox diving class.

Quick background: Your average scuba cylinder contains compressed air, composed of (essentially) 21% oxygen and 79% nitrogen. This combination works perfectly at saturation (ie under a constant pressure, ie at the surface, or at a constant depth underwater), but the high concentration of nitrogen can cause the bends if pressure decreases too rapidly (again, think bottle of soda, shaken: opened slowly [replicating slow gradual ascent], bubbles dissipate without much drama; opened quickly [replicating bolting to the surface], bubbles come out of solution too quickly, and spill all over ever'thing. "The Bends" is caused by pesky, though initially tiny, nitrogen bubbles not being able to gradually dissolve from within the tissues back into the blood stream and out through the lungs, but rather coming out of solution quickly, increasing in size, and shooting willy-nilly into tissues, joints, veins, arteries, etc.).

So, Nitrox is a breathing mixture with an increased percentage of oxygen (typically 32% or 36%, as opposed to the 21% in compressed air/scuba cylinder breathing mix), which is overall safer for a diver to breathe, because less inspired nitrogen means less chance for errant and wayward nitrogen bubbles. I actually earned this cert in Thailand, but I don't remember any of it. Plus, what diver doesn't want another plastic card in her wallet? We have another in-class session for the class, and then hallelujah, we get to do checkout dives, which means a glorious day of diving from the Spectre.

1 comment:

chinadoll said...

Duh. I should have just read your blog!

xEJ