February 2008

By Michael Ange

Q: How do divemasters orientate themselves underwater and find their way back to the anchor or mooring line? I'd like to have the confidence to dive independently with my son and daughter and still locate the entry point at the end of the dive. Without local knowledge of the site, is there a safe method for certified divers to find their way around?

A: There are two basic navigation methods: compass and natural. I won't get into compass navigation here because a navigation class is the best way to get hands-on training with a compass underwater. However, natural navigation (also covered in a navigation class) is a great way to get around in clear water, and many divemasters rely on this skill almost exclusively whether they know a site well or not. Here are a few tips:

Start at the anchor or mooring, and try to follow distinct lines, like the line where the reef meets the sand, so you'll know exactly where you came from.

Slow down your swimming and look around you all the time, making mental notes of landmarks that catch your attention--oddly shaped rocks, a coral growth in a sand flat, a red sea fan surrounded by yellow ones--and use them as markers on the way back.

Most important, don't go very far. The reef under your boat really isn't much different than the one 300 yards away, so swim slowly and stay close. One good method is to imagine you're diving along the radiating spokes of a wheel with the boat at the center. Swim along one spoke for 10 minutes; then turn around. When you get back to the boat, swim along another spoke and turn around--and so on until it's time to go up.

If all else fails, and you're in relatively shallow water, you can do what the divemasters discreetly do in a pinch: pop up for a boat check, get your bearings and drop back to the bottom for the swim home. Good luck finding your way.

Q: I've been diving for years and am certified as a rescue diver. I've asked numerous instructors, but no one has given me a credible answer to this question: Why should you never place your mask on your forehead, but rather always place it around your neck when it's not on your face? "Just because" really doesn't hack it.

A: What your instructors should tell you is to keep the mask on your face until you're completely out of the water. Why? Because drowning sucks. Keeping your mask on seems a small detail, but a poorly timed wave in the face as you breathe in with the mask perched on your forehead can spark a panic attack that can lead to disaster.

Also, dive professionals, simply as a result of practical experience, often recognize a mask on the forehead as a sign of distress. Experienced divers don't remove their mask on the surface (with rare exceptions, like instructors who have to deliver briefings in calm conditions), but it's typically the first thing panicked divers do in a misguided effort to breathe more freely. When anxiety-ridden divers rip their masks off, they often drop them in the first convenient place--their foreheads. Therefore, diving professionals assume that someone on the surface with a mask on his or her forehead is either inexperienced and in need of guidance, or in trouble and in need of assistance.

Finally, your forehead is a precarious place to leave your mask. If a wave crashes over you, the mask may fall off and sink to the bottom. That's why instructors recommend putting your mask around your neck if you have a good reason for taking it off your face.

See "Lessons for Life: Sweating the Small Stuff" (Jan. 2008) for more on why you should leave your mask on until you're out of the water.

Q: I'm new to diving, and I have all my own personal gear (wetsuit, fins, mask, etc.) and a new weight-integrated BC. Now I'm looking for a regulator, alternate air source, gauges and possibly a dive computer. What should I look for in these items?

A: The first step is making some general decisions about how you want to configure your gear. Let's take each one in turn.

Gauges and Computers: Most likely, the rental gear you used in your certification class included a pressure gauge and a depth gauge (and possibly a compass) mounted in a console and attached to the end of a high-pressure hose. If you're comfortable with this arrangement, look for a compact console that's easy to read and that will clip off neatly to your BC for a streamlined swimming profile. You can also choose to replace the gauge console with an air-integrated console computer like the one pictured. These computers provide the same depth and tank pressure information as analog gauges, as well as other dive data, including no-decompression times, bottom time and ascent rate information. Another option is to keep the traditional analog gauge console and purchase a wrist-mounted dive computer. And a fourth option is to replace the hose-mounted instruments altogether with a wireless air-integrated computer. With this style of wrist-mounted computer, you replace the high-pressure hose with a small transmitter unit that displays tank pressure on the computer's screen along with all the other dive data. Which option you choose is really a matter of personal preference limited only by your budget. The staff at your local dive center can help you consider the different configurations and the prices for each one.

When considering which computer to buy, I recommend getting a nitrox-capable computer, even if you aren't yet nitrox-certified. Most of the computers on the market today come nitrox-ready, so it adds little to no cost and you have a computer to "grow into" if you become certified to use oxygen-enriched breathing gases later in your diving career. For more information on the latest in dive computers, see: www.scubadiving.com/gear/divecomputers.

Regulator: Most brand-name regulators sold at reputable dive outlets deliver very good to excellent breathing performance, so again, personal needs and preferences come into play. There are two parts to consider in every basic regulator package--the first stage, which connects to the tank and delivers the high-pressure air to the diver at a usable pressure; and the second stage, which includes the mouthpiece, any user adjustment knobs and the purge valve. A regulator has either a diaphragm or piston first stage. This distinction refers to the way in which the regulator mechanically senses the surrounding water pressure and regulates the pressure of air to the second stage. They both work fine, and environmentally sealed systems of either type will prevent freeze-up if you're diving in cold water.

Choosing a second stage gets a bit more complicated. The biggest choice you'll face is whether to purchase a regulator with user adjustments or stick to a simple, nonadjustable model. This is another area of personal preference as recent Scuba Lab tests have found top performers in both categories (see: www.scubadiving.com/gear/regulators). There are two types of user controls to consider: dive/pre-dive switches (more accurately called venturi adjustments) and breathing resistance knobs. Many adjustable regs have both. If you go the adjustable route, I personally recommend a venturi switch, which can be used to prevent free-flows at the surface. Just remember to select dive mode as you descend in order to gain the highest breathing performance. It's also my opinion that breathing adjustment knobs have very little purpose for most divers. If a regulator is properly tuned by a qualified technician--as it should be--it's probably already set at the easiest breathing position. Ask any diver who has a regulator with an adjustment knob, and he or she will likely admit to either ignoring the control or always diving with it fully open.

Alternate Air Source: The alternate air source decision comes down to whether you choose a standard octopus or an alternate-air inflation system. You probably used an octopus--a backup second-stage regulator--in your certification class, and it's a good choice for your first set of gear. Octopus regulators are usually the same basic design as a primary second-stage regulator, but with slightly higher breathing resistance, to reduce free-flows, and brightly colored purge covers and/or hoses for easy visibility. They're simple to use, inexpensive and familiar to most divers. Just be sure to secure the octopus to your BC to avoid dragging it across the reef.

An alternate-air inflation system is a bit more complex, combining a regulator with your BC power inflator. This allows you to eliminate a hose and a piece of equipment hanging on your BC. Of course, these benefits come with trade-offs. In an air-sharing emergency where you are the donor, you have to give away your primary regulator--the one in your mouth--since the alternate regulator attached to the BC inflator hose is too short to hand to another diver. You then switch to the alternate. This is an entirely different procedure from the one you learned in open-water class, and the relatively short alternate-air inflator hose tends to restrict head movement while you're breathing on it. Additionally, it also takes some practice to learn how to control your buoyancy while breathing from these units. While there are a number of exceptional alternate-air inflator regs on the market, I would recommend that you--as a new diver--stick to the type of octopus you used in training, or at the very least, get a good orientation from an instructor if switching to a new type.

One overall piece of advice: It's a good idea to have a regulator and octopus package from the same manufacturer in order to simplify annual servicing.

Q: I was an avid diver for more than 15 years until I moved back east. It's now been a few years, and I feel like some things may have changed and my skill set and confidence are a little low. Would you recommend a refresher course?

A: Welcome back to the sport! In the old days, when you and I got certified, refresher courses either didn't exist or were a fledgling idea. Fortunately, today they're a staple of the industry. You're correct to assume things have changed over the past few years. Today, dive computers are far more common than dive tables for monitoring your depth and bottom time, and new equipment designs have led to some dramatic changes in the layout of your dive gear; weight-integrated BCs, for example, are a common fixture these days, making weight belts less common. Even ascent rates have changed--the 60-feet-per-minute rule was recently replaced with a safer, more conservative 30-feet-per-minute rule. So, a comprehensive refresher course is an excellent idea. In fact, depending on where you dive it may actually be a requirement, as many operators won't let you dive unless you've been in the water recently or completed a sanctioned refresher course. You can usually complete the course in one afternoon, and depending on the dive shop, you may do an open-water dive as part of the class. The basic refresher course combines a classroom session, reviewing materials from the certification class, with a shallow dive in a pool or off a beach where you can get reoriented with the gear and standard skills like mask- and regulator-clearing, buoyancy control and emergency procedures. Your instructor should allow you enough time to practice these skills until you feel comfortable. If an open-water dive isn't part of the class, but you still want a little extra guidance, talk to the divemaster and stick close to him or her on your first few dives.

Got a question you need answered?
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