Friday, January 14, 2011

Ear To The Ground

Lemme see...glands swollen, nose running, throat scratchy...yup! It appears I've caught a cold of some sort! Fortunately, it doesn't seem to be an horrific one so I should be back diving shortly.

Yesterday, I attempted to visit a site that I've dived before by drifting over to it, but that usually meant I was about half-way thru my dive and was about to turn around anyway. I attempted to jump in (so to speak) and drop in on the Cliff site.

Bonaire is pretty unique for a Caribbean island in that it doesn't have deep wall dives, that is to say the coral and reefs slope rather gently down, making Bonaire a very safe place to dive if you worry about falling off into the depth by accident: you just stay a few feet above the reef and you can pretty much go as deep as the PADI police will allow.

Cliff is one of this rare sites that allows you the sensation of flying, even if it bottoms out at about 55 feet. It is a wall to be sure (along with the Small Wall site, practically next door) and so you can get a sense of wall diving in a very safe environment.

Wall diving is different from reef diving in the sense that on a reef, your attention is pretty much forced down in front of you, while on a wall, you're looking out and up mostly. Too, you can "stand" in front of the wall and take some of the load off your back without kicking coral.It just feels more natural, like browiswing a bookstore.

I slipped under the waves and almost immediately an alarm went off in my head: my ear felt like someone pierced it with a hot poker. If you've ever had an earache or ear infection (I have had both), you know the feeling.

A little physics: diving requires the body to be under pressure. At the surface, the pressure on your body is about 14 psi. Your body is adapted to this, and you never notice it.

Also, your body is an ugly ugly bag of mostly water...OK, in some cases of my female readers, not ugly at all. Anyway, liquids are infinitely compressible. I can take a gallon of water as deep as I'd like and it will become as dense at a thousand feet as the surrounding water.

Where humans have a problem is in any chamber of their body that contains gases.
Lungs, sinuses, ear canals. Because we can't extract air from water, we have to carry a tank of it on our backs. Since we could not possibly carry a sac filled with enough air for an hour's breathing, we force the air into a compact container.

As you decrease the volume of a given amount of gas, you increase it's pressure and here's where it gets tricky. The lungs, being flexible bags, usually don't have a problem adjusting to the regulated pressure you breathe underwater (unless you have a cold which creates a dead air space, but you'll understand that in a second).

But because things like the ear canal and sinuses are essentially caverns, you can trap surface pressure air in them as you descend. Meanwhile, the higher pressure water around you is pressing against them, creating what's called a "squeeze". You feel this most intensely in your ears, because the ear drum is all that stands between that water and that under pressurized air, and the water is pushiung hard against it.

Something's gotta give, and unless you can find a way to get equal pressure into your ear canal, your ear drum will pop if you go deep enough.

You don't need a tank even to prove this: go to any swimming pool, take a deep breath and try to swim on the bottom. You'll feel a gentle pressure against your ear drum.

Divers equalize by forcing the higher pressure air they are breathing into those spaces using techniques they are taught in classes. But if you have a cold, a sinus infection, or something blocking the way, you can't get the newer air in.

This is essentially what happen to me at around ten feet. I did complete an hour long dive and did manage to make it down to 35 feet, but I did not do this at Cliff. I swam along the top of the wall until i could slowly descend. Exertion helps your adrenaline clear your congestions, so that was the only way I could equalize at all.

Meaning I missed the dive I was most looking forward to making.

I's OK. Things happen and as it turns out, I have another week down here to get better and do that dive again.