Last night and tonight, I attended a dive planning "mini" taught by Joe Talavera of Breakthru Diving, through Northwest Sports Divers.
I didn't have tremendous expectations of the class. I'd done Bob's gas management seminar, and I'd had the gas management stuff in Fundies, so I figured it would primarily be review. But I was signed up for the Rec 2 class with Joe over the weekend, so I thought I'd show the flag by being there for the mini.
Boy, was I wrong.
When you boil it down to the very basic facts, the class had no "new" material in it. But that's like saying that all photographs of Half Dome are equivalent -- It's just not true.
We started out by doing about half an hour of . . . mental ARITHMETIC!!!! Yes, things like 3.69 x 4.25. Doing reasonable approximations and using quick tricks for getting the answer. Why is this relevant? Because, for doing gas planning, you're going to be using SCR's in the .75 range, and things like 4.5 ATA, and you need to be able to do the math quickly and accurately ENOUGH, and in your head. Unless you carry a calculator or a pad of paper to the dive site, which I don't.
Then we talked about Rock Bottom, which anybody can understand if they read lamont's beautiful discussion, so why talk about it again? Because it isn't etched in stone. Because there are assumptions built into the calculation, and you need to know what they are, and under what circumstances they would need to be altered, and how you can alter them. (I loved this -- In my surgical training, protocols drove me crazy, because they allow relatively untrained people to function correctly in the circumstances where the protocol is valid, but you have to know what the origin of the protocol was to know when you are facing an exception which needs to be treated differently. This was the entire thrust of this part of the class.)
Then we talked about consumption at depth, and tank factors (how many cubic feet per 100 psi) and how you can use that information to figure out how much gas you SHOULD be using per five minutes, and what issues you should look for if your consumption isn't matching your estimate.
And then, tonight, we did gas planning scenarios for dives of various depths, using various tanks, and various consumption rates. We talked about halves and thirds, and dissimilar tanks and matching.
Five hours (or a little more) about dive planning. I wouldn't have believed that somebody could keep me utterly fascinated (AND absorbing new stuff) for five hours on the subject. I've got the academics cold. The class gave me the pragmatism, and reiterated that "no plan survives contact with the water", and that a thinking diver can adjust and reevaluate as needed, when Murphy comes to call.
A wonderful class.
Anybody who has the opportunity to attend a session like this with Joe should do it. I've been exposed to some absolutely first-class diving instruction, and this session was right up there.
I didn't have tremendous expectations of the class. I'd done Bob's gas management seminar, and I'd had the gas management stuff in Fundies, so I figured it would primarily be review. But I was signed up for the Rec 2 class with Joe over the weekend, so I thought I'd show the flag by being there for the mini.
Boy, was I wrong.
When you boil it down to the very basic facts, the class had no "new" material in it. But that's like saying that all photographs of Half Dome are equivalent -- It's just not true.
We started out by doing about half an hour of . . . mental ARITHMETIC!!!! Yes, things like 3.69 x 4.25. Doing reasonable approximations and using quick tricks for getting the answer. Why is this relevant? Because, for doing gas planning, you're going to be using SCR's in the .75 range, and things like 4.5 ATA, and you need to be able to do the math quickly and accurately ENOUGH, and in your head. Unless you carry a calculator or a pad of paper to the dive site, which I don't.
Then we talked about Rock Bottom, which anybody can understand if they read lamont's beautiful discussion, so why talk about it again? Because it isn't etched in stone. Because there are assumptions built into the calculation, and you need to know what they are, and under what circumstances they would need to be altered, and how you can alter them. (I loved this -- In my surgical training, protocols drove me crazy, because they allow relatively untrained people to function correctly in the circumstances where the protocol is valid, but you have to know what the origin of the protocol was to know when you are facing an exception which needs to be treated differently. This was the entire thrust of this part of the class.)
Then we talked about consumption at depth, and tank factors (how many cubic feet per 100 psi) and how you can use that information to figure out how much gas you SHOULD be using per five minutes, and what issues you should look for if your consumption isn't matching your estimate.
And then, tonight, we did gas planning scenarios for dives of various depths, using various tanks, and various consumption rates. We talked about halves and thirds, and dissimilar tanks and matching.
Five hours (or a little more) about dive planning. I wouldn't have believed that somebody could keep me utterly fascinated (AND absorbing new stuff) for five hours on the subject. I've got the academics cold. The class gave me the pragmatism, and reiterated that "no plan survives contact with the water", and that a thinking diver can adjust and reevaluate as needed, when Murphy comes to call.
A wonderful class.
Anybody who has the opportunity to attend a session like this with Joe should do it. I've been exposed to some absolutely first-class diving instruction, and this session was right up there.
I know this is because of several factors that include 1) temperature decrease at depth 2) wing inflation during descent and 3) my breathing rate slows down once I get to the bottom- sometimes, there is a little work involved near the surface.
