Checking Your Buoyancy at the Surface If you are properly weighted, you should be able to hover at 4 meters (15 feet) with 34 bar (500 psi) or less of air in your cylinder. You must test your buoyancy at the surface before you begin your dive. To test your buoyancy for scuba diving, use the following steps: 1. Make sure that your BC is completely deflated. 2. Assume an upright position in the water. 3. Take in a deep breath and hold it while you hang in the water motionless. If you are properly weighted, you will float at eye level. 4. Exhale completely. If you sink, you are properly weighted. 5. As soon as you sink, kick back to the surface and inflate your BC. This procedure gives you an approximation of correct buoyancy adjustment. You will fine-tune your buoyancy adjustment as you gain experience in using different types of equipment (for example, exposure suit worn, type of cylinder used, and size of cylinder used) and diving in salt and fresh water. Your buoyancy will change during your dive because of the compression of your diving suit, the amount of air in your BC, the items you collect during your dive, and the use of air in your cylinder. You will control your buoyancy during your dive by adding to or removing air from your dry suit or BC. Descending Being able to descend easily in the water is one of the important skills of diving. Diving is not much fun if you have to struggle to get to the bottom. Some of the general steps for descending are: 1. Have your regulator in your mouth. 2. Note the exact time that you leave the surface. If you are using a dive computer, it will automatically start timing your dive when you leave the surface. However, a dive computer does not always record the time of day you leave the surface. Having a slate or your dive table in your BC pocket is a good place to record the time. 3. Deflate your BC. If you are weighted correctly, Chapter 3- Diving Skills you will slowly sink when all the air is removed from your BC and you exhale. Remember to hold the power inflator hose over your head and watch its mouthpiece to see the air coming out as you go under water. Stop pressing the deflator/oral inflator valve button when you do not see any more air to prevent large amounts of water from entering the BC. 4. Equalize your ears as you start your descent and continuously throughout your descent (figure 3-45). Never continue descending if you feel pressure in your ears and you cannot equalize them. You will not feel discomfort if you are equalizing properly. 5. Exhale and begin your feet-first descent (figure 3-46). Remember to breathe out completely and then take in a small breath of air. The less air you have in your lungs during the first few feet of descent, the easier your descent will be. If you descend feet first, you can maintain better contact with your buddy and it will be easier to equalize pressure in your ears, mask, and sinuses. 6. Stay with your buddy as you descend. Remain close enough to touch each other and maintain eye contact throughout the descent. If one buddy is having trouble equalizing, the other buddy must be patient and wait with them until the problem is corrected. Diving Skills 73 FIGURE 3-45. REMEMBER TO EQUALIZE EARLY AND OFTEN DURING YOUR DESCENT.
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