Chapter 10- Diving Techniques and Deeper Diving Diving Techniques and Deeper Diving 233 amount of weight required to neutralize this buoyancy in water. Your guiding principle should be to use the minimum amount of weight which will provide neutral buoyancy at 5 m (15 ft) of depth with an empty buoyancy compensator and a nearly-empty cylinder. This ensures the ability to execute a precautionary safety stop at 5 m (15 ft) at the end of a dive without risking premature surfacing. Take the time to make the necessary determinations, perhaps at the end of your next dive. The most common method of carrying required weights is on a weight belt with standard webbing, lead shot-filled, or with pockets. Whichever you choose, some basic principles apply. A weight belt should have a quick release buckle. The majority of the weight should be equally divided. Attach one or two weights just in front of your hips. Your cylinder constitutes a significant weight at your back, and better vertical and horizontal balance is achieved by placing weights in front of the hips. Ankle weights may be appropriate with dry suits. Ankle weights add a small amount of weight to each ankle. However, ankle weights can also add significantly to the comfort of wet suit and other divers, especially those using light, floating plastic fins. Ankle weights also keep your feet submerged for more effective snorkeling. Some systems employ weights integrated with the backpack and buoyancy compensator. These systems either eliminate the necessity for a separate weight belt or allow the amount of weight worn on the belt to be reduced. The use of such a unit involves several important considerations. You should have training in its use and maintenance. You and your buddy must be thoroughly familiar with the weight release location and method of operation. Also, the weights may require maintenance, since salt buildup and corrosion can reduce the efficiency with which the weights can be jettisoned from some systems. The weight of the entire unit (cylinder, buoyancy compensator, and weights) usually exceeds 20 kg (45 lb), which some people find excessive. Loss of Buoyancy Diving with excessive ballast is dangerous. The added weight demands extra energy to move from one point to another above or underwater, more air is needed in your buoyancy compensator to achieve buoyancy, and extra energy is needed to push the over-inflated buoyancy compensator through the water. Many modern BC’s can provide as much as 20 kg (45 lb) of lift. They should not be used to compensate for overweighting. Overweighting adds to your stress in the event of an occurrence requiring extra effort (long surface kick, increased currents, wind, buddy needing assistance, etc.). Additionally, if the BC malfunctions or fails to hold air, an overweighted diver may be in a life-threatening situation. If the diver is unable to control descent and is too heavy to ascend, then the weight belt must be ditched. A rapid ascent can be slowed by assuming a horizontal flare position to create drag. This should be practiced only in confined water under the supervision of an instructor. Excessive Positive Buoyancy If the weight belt is ditched or the power inflator on the BC becomes stuck open, buoyancy will be quickly evident. Many divers wearing dry suits and thick wet suits can wear more than 15 kg (33 lb) of weight. A BC can be filled to maximum capacity within a matter of a few seconds, producing more than 20 kg (45 lb) of lift. Loss of a weight belt at depth is not uncommon. A sudden increase in buoyancy should trigger immediate emptying of the buoyancy compensator and checking of the weight belt (see Emergency Ascents section in Chapter 6). If your weight belt comes off underwater, you should immediately kick down and grasp the weight belt. To replace a weight belt, lie face down, hold the buckle in one hand, place it on that hip, and roll to the other side down, until the weight belt wraps across your back. Supporting the weights on your back makes it easier to secure the strap in the buckle. In the case of the power inflator sticking open, the low pressure hose should be immediately disconnected. Air should be vented from the BC immediately via the
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