Atlanta Underwater Explorers AUE Bubbles

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1 Atlanta Underwater Explorers The Atlanta Underwater Explorers, P. O. Box 55048, Atlanta, GA September 15, 2017 Volume 5 Issue 5 I N S I D E T H I S I S S U E 1What To Do If You re Left Behind 2 & 3 The Secret to Neutral Buoyancy 4 & 5 How a SCUBA Diving First Stage Regulator Works 6 AUE Activities, News, Events & Announcements What to Do If You re Left Behind By Sport Diver Editors You surface after a great dive, but the boat is nowhere in sight. What do you do if you're left at sea by the boat after scuba diving? Do you know what to do if you're left by the boat? STEP 1: Look Again Don t panic. The boat could be close by, but you missed seeing it. Even small chop makes waves higher than your head, and unless you re looking the right way at the right time you can miss a boat only 100 feet away. Inflate your BC so that your head is as high as possible and do a slow 360-degree inspection of the horizon. If you find the boat, and its close enough to swim to, take a compass bearing and submerge to about 15 feet. Your fins are far more efficient making full strokes under water than splashing on the surface. Inflate your BC so that your head is as high as possible and do a slow 360-degree inspection the horizon. STEP 2: Signal Still can t see the boat? Or maybe you can see the boat but a current prevents you from swimming to it? If it's the latter, a crew member may be able to see you. Help by making both visual and auditory signals. We ve found a serviceable visual signal to be an inflatable safety sausage, but failing that, take off one of your brightly colored fins. Wave it vigorously, including splashing with it; motion attracts attention. Use an auditory signal like the Dive Alert air horn. Deflate your BC enough to submerge your ears before sounding, however. The blast can damage your hearing. A simple whistle can also be effective in the right conditions. If the boat is nowhere in sight, it may be that surface chop is heavy enough that it's preventing you from spotting the boat, and the boat crew may be having the same difficulty in seeing you. In these cases, audible signaling devices are especially helpful. This is why it's best to carry both visual and audible signaling devices when diving. For details visit this website:

2 Page 2 The Secret to Neutral Buoyancy Underwater By Aleksandra Bartnicka There's no denying that peak performance buoyancy control separates the dive paddlers from the pros. When all the big talk is over and the water closes over your head, there is nothing that pulls the whole scuba diving thing together like perfect buoyancy control. The secret is pinpoint buoyancy control, and it all begins with fine-tuning your weighting that's how much lead you thread on your belt or put into your pouches. If you are carrying just the right amount of weight, you will have the smallest amount of BC inflation. That means less drag and more efficient finning. Less BC inflation also means less buoyancy shift with depth, so you'll make fewer adjustments. There are many tricks, but pinpoint buoyancy control is the fundamental skill. Precise control of your buoyancy is what enables you to hover completely motionless and fin through the water, at any depth, without using your hands at all. It sounds easy, so why isn't it? In fact, pinpoint buoyancy control requires getting more than one thing right. The factors that affect your buoyancy besides ballast weight are BC inflation, your trim, exposure suit, depth and breathe control. Your ballast weight and your trim are the only two factors that, once you've selected them, stay put. All the others are variables, changing during the dive along with time or depth or both. Some you can control, some you can't. Here is our advice for getting perfect neutral buoyancy so you can enjoy your time underwater without fiddling too much with your BC inflator hose. Take a course. PADI offers a course in buoyancy and weighting called "Peak Performance Buoyancy." The course teaches precise buoyancy control, streamlining, weight and trim adjustment, equipment configuration options and relaxation techniques.- Pre-dive preparation. Real buoyancy control begins, as does any dive, with pre-dive preparation. As you pack and check your equipment, double-check to make sure nothing has changed that could affect initial weighting. New wetsuit? Major factor. Nice, springy wetsuits need more weight than old rancid flatties. A fresh suit has more inherent buoyancy at first because diving, especially deep diving, simply bursts its bubbles. New BC? Unlikely to have a major effect at this point, but it will in the water. New weight belt? Maybe a nifty new shot belt? Take a moment to make sure the new compares well to the old. Stick'em on a bathroom scale; often there is variation between claimed and actual weight. New cylinder? Another biggie. Some cylinders are negatively buoyant when full and simply less negative when empty; others sink first and float later.

3 Page 3 The Secret to Neutral Buoyancy Underwater Cont. Do a buoyancy check. Here's how to make a proper buoyancy check: With your lungs half-full, you should float at eye level with no air in your BC. But the fact that your average cylinder loses about 5 pounds as it empties gets you thinking about the buoyancy change in a tank and is a good reminder that it's best to do a buoyancy check with a nearly empty cylinder before you dive. This is obviously a bit of a pain, so add about 5 pounds to your weight if you have done your buoyancy check with a full one. You can always take a moment and recheck buoyancy after a dive, just before you get out of the water. See the Buoyancy Calculator ( for more tips on being properly weighted. If you you're over weighted because you struggle with descents, read How To Take Off Weights ( for tips on getting down without adding weights. During the dive. Now for the dive itself. Understand why feet-first descents have many advantages: One is that it's easiest to completely empty your BCD in this position. Double-check that the point where the deflator hose attaches to the bladder is really the closest point to the surface as you prepare to descend. It's often helpful to dip your opposite shoulder. Exhale, and if you're properly weighted, you should sink slowly. Keep your hand on the BC inflator and get ready to add controlled bursts of air to adjust your descent rate. You'll add more as the descent continues. If you're making a deep dive for the first time, it can be a bit of a surprise to see just how much air you have to add as you continue. During the dive, enjoy the fruits of your labor. Concentrate on what happens as you breathe. If you see something interesting below you, exhale and drift down for a look. Inhale and you'll level off and start to rise. Don't vary your breathing habits too much, though; breathing slowly deeply and continuously is of primary importance. During the ascent. Keep the point about BC positioning in mind while making gradual ascents too. It's easy to trap some air in an unfamiliar BC, which will continue to expand as you ascend. On deeper dives, and given neutral buoyancy, you should only have to start swimming up a little before expanding air takes over. Make sure you're ready to vent this off as needed. Make the safety stop count. The goal is to be neutral while doing your end-of-dive safety stop, so that's when you can really fine-tune your buoyancy. As you near the surface, stop at 15 feet. After three minutes, kick slowly for the surface. If you have done everything right, there should be no air in your BCD as you break the surface. You should also now be floating at eye level, rising a little as you inhale and sinking slowly as you exhale. If this is not the case, make appropriate adjustments before your next dive. Log it. After each dive, write down what exposure suit you wore, what equipment you used, how much lead you carried, how much your body weighs and whether you seemed too heavy or light at your safety stop. SALT WATER VS. FRESH WATER WEIGHTING If most of your diving is done in freshwater springs or lakes, then ballast calculations should be done in freshwater. If you dive mostly in the ocean, then do the calculations in saltwater. If you switch back and forth, you ll need to adjust your ballast needs as you go. Be prepared to add anywhere from 4 to 7 pounds going from fresh to saltwater. See our Buoyancy Calculator for more details on making the weighting conversion between saltwater and freshwater. For details visit this website:

4 Page 4 How a Scuba Diving Regulator s First Stage Works By Floyd Devine Piston First Stage 1. The Parts Both piston and diaphragm regulators have either a DIN or yoke style fitting to connect them to the scuba cylinder; an inlet filter to prevent contaminants from entering the regulator; a regulator body incorporating intermediate- and high-pressure chambers; a bias spring; medium-pressure fittings for second stages, inflator assemblies, and accessories; and high-pressure fittings for gauges and transmitters. Piston regulators have a piston-style valve assembly with a high-pressure seat separating the first stage s high- and intermediatepressure chambers, while diaphragm regulators have a diaphragm, lifter-poppet valve assembly and highpressure seat performing the same function. 2. How It Works As you inhale on the regulator s second stage, pressure in the first stage s intermediate chamber is reduced. The force of the bias spring and the ambient water (hydrostatic) pressure push inward on either the diaphragm or the base of the piston head, raising the valve and creating an opening between the intermediate- and high-pressure chambers. Air flows from the high-pressure chamber into the intermediate-pressure chamber and down to the regulator second stage via the connecting hose. When the diver stops inhaling, pressure inside the intermediate chamber increases until it is greater than that of the bias spring and hydrostatic pressure and the valve closes. The first stage is designed to provide air at ambient pressure, so it must adjust for the changes in pressure as depth changes. To do this, a method is needed for the valve assembly to sense the ambient pressure changes and adjust accordingly. Piston regulators have the bias spring, the underside of the piston and a portion of the piston shaft exposed to the water to provide the hydrostatic pressure necessary for operation. Diaphragm regulators have one side of the diaphragm and the bias spring in contact with water to provide hydrostatic pressure but the rest of the components are sealed off from the environment on the other side of the diaphragm. In both cases, the amount of pressure required to open and close the valve assemblies varies with the ambient water pressure on the exposed surfaces. 3. Balanced vs. Unbalanced A balanced first stage, whether piston or diaphragm, is designed so that tank pressure does not impact the operation of the valve. This ensures consistent breathing effort independent of depth or tank pressure. Currently, all diaphragm regulators in production are balanced. In diaphragm systems, balancing is accomplished by routing intermediate-pressure air to both sides of the complete valve assembly and passing the valve stem through both the high-pressure and intermediate-pressure chambers.

5 Page 5 How a Scuba Diving Regulator s First Stage Works Cont. In balanced piston first stages, the incoming high-pressure air does not directly act on the piston-valve, which also passes through the intermediate and high-pressure chambers. Unbalanced regulators have tank pressure acting directly on the high-pressure seat, and incoming high-pressure air will act to close the valve as intermediate pressure rises. This works fine while tank pressures are high, but can result in heavier breathing resistance when at higher ambient air pressure (deeper water) or when tank pressure is low. The unbalanced piston will still provide adequate air supply in these cases, but it will require more effort by the diver to breath. 4. Piston vs. Diaphragm Now to the eternal debate over which is best: a balanced piston or diaphragm first stage. In reality, it boils down to a matter of personal preference and both designs work well at providing breathable air to their users. There are some distinguishing characteristics, however, that may aid in deciding which may be best for you. The nature of a diaphragm first stage s design means that it is environmentally sealed. There is less chance of components being affected by ice particles in cold water, or by silt, sediment or other contaminants in turbid waters. Diaphragm regulators tend to be complex with more parts than a piston regulator and have a smaller diameter valve, meaning lower overall volume of air to the second stage. Piston regulators are of simpler design and the size of the piston stem allows for a larger volume of air to be supplied to the second stage, making them popular for their ease of breathing effort. Piston regulators have more components exposed to the environment, making them more susceptible to contaminants affecting performance, icing in cold water and resulting free-flow from a stuck piston. Piston regulators may require more maintenance of exposed parts due to contamination. 5. Additional Features Regulator first stages are closed systems and are not designed with user-adjustable features, but there may be enhancements incorporated by the manufacturer. Both types of regulators may incorporate environmental protection, to include a second diaphragm to protect the bias spring of a diaphragm first stage, or by filling the exposed section of a piston regulator with a viscous fluid and sealing it off with a flexible ring. Some regulators incorporate automatic devices to close the high-pressure inlet and prevent contaminants or water from entering the first stage when the regulator is not connected to a tank. Some regulators may incorporate a special medium-pressure port with greater airflow specifically designed for high performance second stages. For details visit this website: m=trueanthem&utm_source=facebook#page-2

6 Page 6 Upcoming AUE Activities AUE General Meeting Saturday September 16, 2017 Location: 1463 Prior Rd SW, Atlanta, GA Meeting time is 3:00 p.m. every 3 rd Saturday of each month. AUE Annual Panama City Beach Dive With DIVERSe Orlando - Dive the Famous Wrecks of Panama City Beach, Florida Friday-Saturday, September 22-23, 2017 During the weekend, we plan to visit the Man in the Sea Museum. See SEALAB 1 and a large collection of rare diving equipment highlighting man s success in underwater exploration capabilities. Contact: Erik Denson Phone: (407) edenson@cfl.rr.com AUE General Meeting Saturday October 21, 2017 Location: 1463 Prior Rd SW, Atlanta, GA Meeting time is 3:00 p.m. every 3 rd Saturday of each month Annual NABS Summit National Association of Black SCUBA Divers 27th Annual Dive SUMMIT at Ramon s Village Resort Ambergris Caye, Belize November 4 thru 11, _Information_Sheet.pdf Recent AUE Activities AUE s Annual Cookout August 5, 2017 AUE Member training session for youth diver Tyrese Evelyn at Pelham Blue Water Park Saturday July 1 st and Sunday July 2, Participants included members of Youth Diving With A Purpose, Gerald Jones, Dive Instructor and AUE members Elleen Yancey, Alex Adams & Chris Searles. Tyrese is in training to acquire the skills to become a scientific diver. Conasauga River Snorkel Trip + Brief AUE Club Meeting June 17, 2017 Announcements/News Fellow AUE Members: Club News Update: AUE Member Chris Searles featured in article titled Diving into history and mystery. News article is located on the AUE s website. AUE Member Marie Richardson will provide an update at the September 16 th AUE club meeting. Marie will discuss her recent trip to Antarctica. Announcement: There are local diving opportunities: Blue Water Park (Two hours from Atlanta, GA) Pelham, Alabama (205) (205) More information at: bluewaterparkal@gmail.com or Dive Georgia Open Water Quarry (Forty-Five minutes from Atlanta, GA) April Oct 2 9 T H Sat & Sun. 9 A M - 4 P M 801 Old Tennessee Highway NE White, Georgia Phone: (404) x200 Editor s Corner Atlanta Underwater Explorers Welcome to the September 15, 2017 edition of AUE Bubbles newsletter. The edition is focused on dive equipment and related issues. Want to learn more? Find us on the web at and like us on Facebook at: EXPLORERS and via newsletter. Story ideas are always welcomed. Completed story submissions must be received one week prior to the publishing date (Bi-monthly on the 15 th of the month). The next edition will be published November 15, Please submit future story ideas and comments to my attention via . Bubbles needs your input and support. Dive safely, Alex Adams, Publisher & Editor scuba1aja@gmail.com