Device dependence (was: Cypres report)

[Scrumpot 1]

Quote

By your reasoning, they should be willing to do the jump without any kind of altimeter, either visual or audible. correct?

Before even visual altimiters became reasonable/affordable, people used to jump with stop watches all the time. However, the PRIMARY altitude awareness "device", and still the only one to be ever absolutely relied upon IMHO should be your own 2 eyes. ALL other man-made devices, no matter how fancy and technologically advanced (new-fangled) are none-the-less, subject to failure. To rely on any of these "back-up" devices to an absolute degree of dependence is always a mistake.

That's a long answer in my opinion to this question, which translates I guess into the much shorter direct response of (again in my opinion) YES...

I do think that any jumper should be willing to, or at least be CAPABLE of making a jump at any time, entirely without any kind of altimiter at all. Either visual (mechanical/electronic) OR audible. Otherwise what would they/you do if (or more likely WHEN -inevitably if you participate long enough) that device does fail on you?

JMO,
-Grant

coitus non circum - Moab Stone

[kelpdiver 2]

Grant - no real disagreements to follow, just some ramblings on technology in sports.

Sounds similar to the old days underwater, long before my time, before pressure gauges became common. Divers used simple dials on underwater watches as an estimate of nitrogen loading and air time. Simple hardware like the honker or the J valve might warn them of running low, but were easy to misuse. And I'm quite sure the divers of the day were much better at swimming to the surface on a single remaining breath. They had to be. And the accident rates were much higher, even though the typical diving course was closer to SEAL training than the current Operation Bambi.

Now everyone uses an SPG (submersible pressure gauge) and the general approach is to maintain awareness, and to turn the dive if it were to fail. Even if you have a buddy with, it's preferable to surface. People have died while sharing air traveling to the home target underwater rather than surfacing and dealing with the kelp crawl. Like jumping, air is life, but it's pretty much impossible to estimate your remaining supply based on the bouyancy of the tank.

Fortunately the mechanical SPG is quite reliable, and if it fails, will likely do so during the predive assembly when you charge the lines. Should it fail underwater, the rate of air loss is quite manageable. But with the air integrated computers, it's not so rosy. One technie brand was notorious for eating batteries and failing mid dive. Electronics and cold water aren't a good mix for an essential tool.

Drifting (finally!) back to jumping, you have gauges that seem somewhat less predictable in failures, can't always safely pull immediately on discovery, and can make a decent estimation of height. The catch is that the penalties for screwing up are much more serious. Can't borrow a few hundred feet from a buddy, or kick up 50ft on your own.

I find it a bit wacky going to a place like Elsinore where the exit is 12-13 AGL. Right around door time my alti3 may read exactly 0/12, causing that momentary double take. But from what I've read here, a sticky needle isn't necessarily sticky in both directions - you see it on the way down?

[tbrown 26]

The classic story from the way old days is the guy who figured out that he could see the oranges on the trees at pull time. Worked just great until one week they came along and piked all the oranges !

I've known people who made low pulls back in the seventies when their Altimaster needle got stuck They were waiting for a stupid needle to give them permission to pull, all the while never noticing that things on the ground were getting really HUGE.

I wouldn't call myself dependent, but I'd rather not jump without an altimeter. I've got a pretty good sense of time and usually I shoot my first glance at my wrist mount somewhere between 6 and 7 grand. After breakoff I don't look at my alti again 'til I'm open. Once again, I know I've just broken off at 4 to 5 grand, there are so many people in the air with me and I'm keeping an eye on them as I track to beat hell out of there. I know that somewhere below 3 grand things start getting a lot bigger. And usually I beat the traffic, take a good look around, give a good wave and when I check my alti again under canopy I'm consistently at 2200-2300 ft.

But I wouldn't want to be jumping with people and have to judge the breakoff without an alti, for safety in groups they really are necessary.

Your humble servant.....Professor Gravity !