Our C-cards show that my wife and I were certified on April Fools' Day, 1994. In the 18 months since, we have logged an even 50 dives, in Key Largo, Cozumel, Puerto Rico (including Culebra), and Roatan. Considering that we live in Wisconsin and work for a living, that's pretty incredible. We even have plans already to visit Cayman Brac and Grand Cayman next spring, and Bonaire the following Christmas. By then, our daughter will be 12 and may be diving with us. But for now, I just sit here, trying to come to grips with the 6 month dry spell that lies between now and that Cayman trip, and wonder what it is about diving that is so unbelievably captivating.
We had looked forward to our open water diver's course for quite some time before having an opportunity to take it, and pretty much thought we knew what was in store for us. We had snorkled in the Caribbean for years, first at Isla Mujeres and later Cozumel. We were enchanted by the beauty of the water and the pleasure of returning year after year to one little piece of reef to see what old and new creature friends would turn up this time. I think we expected diving to let us get a little closer and see a little better; that's about it. And it would come with the disadvantage of having to futz with all that stuff that went down with you.
I remember so well our telling our instructors, Kathy and Walter Moore (of Sea Moore in Key Largo) that we would surely never buy our own equipment; rental gear would be good enough for our occasional visits to the subsurface world. Ha! We weren't back in Wisconsin more than about 2 weeks before we had thoroughly examined the wares of the two dive shops in town and bought most of our stuff. In fact, it was a bit disappointing to run out of things to buy- -shopping and studying the gear turned out to be one way of continuing to feel connected.
In short, we were amazed by the magnitude of our passion for diving; though that turned out to be only one of several surprises. Another that struck us right away was how little we were able to share our enthusiasm with non- diving friends before they lost interest; it was as though we were trying to show them old home movies. Suddenly we were even more boring than ever before. We've concluded that, with someone who hasn't been there, it just isn't possible to transfer even so small a joy as the absolute charm of a spotted trunkfish going about its life. Curiously, though, I find that I'm not all that interested in the exploits of other divers either--wrestling with 20 foot octopuses, for example--unless they are experiences that I too have had. Then we can share and it's a real treat.
Speaking of octopuses, I have a friend, Charlie, who is interested in almost everything, including classical languages. He tells me that using 'octopi' for the plural is really bad Latin. It should be 'octopodes', and that speaking in English we should probably just use 'octopuses' . My Wordsworth dictionary, I now find, agrees with him. (By the way, Charlie also tells me that octopuses are reputed to be able to glide through any cracks that will accommodate their eyeballs, the only significantly rigid part of their bodies.)
Another surprise for me was the distinction made between recreational divers and whatever the others are called, professional divers, technical divers, etc. I imagined that there were novices and those with experience, sure, but this is really something quite different, and even brilliant. In my opinion, diving could not be the popular and amazingly convenient and safe activity it is today without the emphasis on this distinction. Whether one wishes to admit it out loud or not, the recreational diver is essentially a tourist in the aquatic world. There is a whole industry of support people for the activity. We take their classes, read their magazines, buy their equipment, travel to their resorts, and dive with their guides. It is similar to traveling to the Grand Canyon, staying in the Lodge, and riding the burros down Bright Angel Trail to Phantom Ranch, or whatever it's called. The biggest difference is that it feels today more like I imagine it felt to make that canyon trip in 1910, when there was still ample adventure left in the tourist experience. In any case, I for one am grateful to those who have blazed the trail, trained the cowpokes, designed and maintained the equipment, built the lodge, and invited me and my family to come enjoy the panorama they have made accessible. I would never have found the time nor daring to have made the journey without them.
Sometimes I feel frustrated that useful information about scuba has to be acquired so piecemeal. I bought the Encyclopedia of Recreational Diving, thinking I would be able to look up whatever I liked, whenever a question came to mind. I figured it would have several more pages of hand signals than found in the open water diver's manual, that it would tell me about when and how dive floats are used, that it would have comprehensive tables of diving injury symptoms and the recommended first aid treatment, and hundreds of other things that I might wonder about. But, surprise, it was a different sort of book. Mostly it seemed to be interested in tempting the reader into taking more courses rather than providing concise information.
So, instead of having a comprehensive source, I find myself muddling along, trying to remember what I wanted to know until one of the magazines gets around to revealing just the right nugget. In this past October's Dive Training, magazine I found Alex Brylske addressing the trim weighting techniques that ought to be able to cure my heavy feet problem. And Saturday, I got a regulator mouthpiece that might keep my jaw from aching and a little disk to glue into my mask that should allow me to see my guages better. One little thing at a time, I will get tuned, eventually.
From having our gas grill's propane tank refilled, I know that the tank's weight is used to determine when it is full. Consider then my surprise on learning that scuba divers, who care and talk so much about proper weighting, do not generally seem to know how much the 3000 psi of air in a tank weighs. Folks regularly tell us that empty tanks are lighter, but not by how much. So I sat down with the perfect gas law in our manual, the roughly 80/20 mix of nitrogen and oxygen in air, and the molecular weights of those molecules (about 28 and 32). I also needed a bunch of conversion factors but they weren't hard to get. The bottom line is that 80 cubic feet of sea level air weighs about 6 pounds, in case you also wondered. When you cram that 80 cubic feet into a scuba tank at 3000 psi (200 atmospheres), it's volume is reduced to about 0.4 cubic feet, but it still weighs 6 pounds. When you suck that tank down to 500 psi before reaching the boat, you have used 5/6ths of the air, or 5 pounds. On the other hand, if your "80" cubic foot tank really holds closer to 70 cubic feet, that 5 pounds of air may actually closer to 4. So let's call it "5", meaning it's as much a 5 as the tank is an "80".
So the probable reason we don't usually much notice the weight of the air in a scuba tank is that the tank itself weighs a great deal more. But does that mean it's unimportant? No way! Notice Alex's advice, in the article I referred to previously, to the effect that a diver should test bouyancy and weighting at a depth of 10 to 20 feet while having a nearly empty tank! Why? Because if you do it with a full tank at the start of a dive, then at the end of the dive, when you want to make a safety stop, you will have "5" pounds positive bouyancy and a hard time hovering there.
But there's another surprise hiding in that information. I know that when I wear just enough lead to sink from the surface with a peaceful attitude, a full tank, and a good exhalation, I also have the right amount to be correctly weighted for that safety stop at 15 feet on the way back, without adding an extra "5" pounds. Why? My tank is that much lighter; why I don't rocket to the surface? I expect it's because my body and wet suit must be compressed to occupy at least 5 pints less volume (have 5 pounds less bouyancy) than they do at the surface. I do get positively bouyant somewhat after leaving the safety stop, but by then, going gradually up is what I have in mind anyway.
Does this "5" pound story have a moral? Yeah. If you use an empty tank to test your weighting at the surface, you'll be carrying more lead than you really want, as much as 5 pounds more. When you dive, you won't have any trouble going down, but when you get there, you'll be fiddling with the air in your BC a lot more than you should have to. (The reason that there is more fiddling when there is more air in the BC is that the volume of that air, and its bouyancy, are much more sensitive to the surrounding pressure, depth, than the rest of you, requiring more frequent adjustment when the depth is changing.) So, if you want to follow Alex's plan, checking weighting with a low tank, you have to do it right, at the safety stop depth, presumably at the end of one dive, preparing for the next. (Except who will hand you the lead to make the adjustments?)
The final surprise of this tale was for us a big one: In 50 dives, my wife and I have each experienced one disturbing incident. In my case, my weight belt fell off at depth. Fortunately, a guide was right next to me and grabbed me as I started up; I got turned over and could kick down to stay in place while he fetched the belt off the bottom, only about 3 feet below me. My orthopedist had told me, a couple of weeks before, that I was crazy for diving, that there had in fact just been a bad incident from someone who had lost his weight belt. It was a little scary then to have it happen to me, though it didn't seem like much right while it was happening. If you know you're going up, what's wrong with kicking down? Perhaps it's a much bigger deal in low visibility if you can't tell you've suddenly started an unplanned ascent. Where in our manual, though, or in any of the magazines, have we been warned to recheck the fit of our weight belts once we have gotten down a ways. My body compresses a good 2 to 4 inches in belt size when I dive (a fact related to that 5 pints I was talking about earlier). If your rental belt is a little worn and the buckle depends on the belt being tight to be reliable, it could pop loose when you go down. So I bought my own belt, with a secure buckle, and I keep a weight clip on it to mark how tight it needs to be for a good fit at depth. And on every dive, I cinch it up to that clip on the way down. But what do you know? Another surprise! It turns out that they make depth compensating weight belts which cinch themselves up! And yet, in our 50 dives, I never saw such a belt used, nor have I seen any offered at the rental counters. What's the deal? Are these useless, am I paranoid, or would the things actually save a life now and then? Should the training manuals not at least mention checking belt fit once on the way down? About that orthopedist who tried to warn me off diving, he is a bike racer who has had a variety of accidents and injuries from that sport, and was examining me for injuries I suffered when a car hit my bike. But he didn't suggest I quit bike riding. I therefore suspect that he may not have an entirely unbiased view of the relative dangers of various activities. Perhaps he doesn't distinguish between responsible recreational diving and the diving of those who, for whatever reason, always need to operate beyond the edge of reasonably good sense.
Ellen's incident was totally different from mine. Once down, she noticed her pressure was low and signaled for me to take a look at her equipment. To my surprise, she was losing air very fast at the tank valve/first stage connection. I wiggled the connection but it didn't get better so I got the divemaster and then gave Ellen my octopus. The divemaster shut off EllenŐs air and managed to reseat the O-ring in just a few seconds, loosening the connection only slightly, jiggling and retightening. It worked fine and we were able to finish the dive, though shortened by Ellen's tank having lost about 1500 psi. (It was our last dive of the trip and she had the reg serviced as soon as we got home in case salt water got into the first stage.) So blame my wife right? Or me. We all are told that we take full responsibility for the condition of our equipment and that of our buddies. But in this particular dive operation, we didn't have access to our equipment. It was set up entirely by the divemaster and boat captain, and plunked on our backs just moments before the back roll. The bottom line is that it is sometimes difficult to know what is required to take full responsibility; in this case it probably meant we should not have dived with people who tried to do everything for us, or we should have insisted on upsetting their usual way of doing things to take time to check their setups. Or maybe, we should take a totally different attitude; there is caution and there is paranoia. Each of these incidents was resolved successfully, with no panic or major trauma. Each gave us a sense of calm confidence in our abilities to cope with surprises, and heightened our senses of security and responsibility. I'm sure we're somewhat better divers for having had them. 'Good divers,' after all, 'are always training."
Following Ellen's incident, I realized that a good test for leaks would be to turn on your air at setup, then turn it off without pressing a purge button, leaving the regulator pressurized. After 10 minutes, if there is no leak, the pressure gauge will still show the full tank pressure. The only danger with this scheme is forgetting to turn the air back on, but a quick purge while looking at the gauge will always remind you whether you left the air on or off. Just never leave it partly on or partly off.
So, did you really want me to try to tell you why Ellen and I are so utterly sold on diving? Is it the fulfillment of childhood dreams of flying, of entering weightlessly into a 3 dimensional world, where suddenly there is up and down to experience, personally? Is it the sense that we are visitors in a world that is as absurd as sci-fi imagining, but vastly more beautiful, intricate, and accepting of our presence? Is it the feeling that we are floating through an enchanted forest, full of fairy castles and a multitude of pleasant creatures at every turn? Is it the sense of flowing through the water that gives a feeling of passage into a different space, as in a dream? Heck, you've been there and know, or you haven't and don't. I can't tell you if you haven't, and you don't need telling if you have.
6 months! My soul could dry, shrivel and blow away in 6 months. Aargh!
But then again, considering what hurricane Marilyn seems to have blown away in the last few days, maybe it's a good time to be home. Raking season is only a few weeks away.