NAUI Master Scuba Diver 26 Diving Equipment materials to resist ozone. This material has fairly good stretch. Patching this material is similar to patching an inner tube or inflatable boat. All dry suits for active divers should be equipped with attached hard sole boots and knee pads. Automatic suit exhaust valves which vent air upon ascent, without manual operation by the diver, are another important feature. Exhaust valves are usually located on a sleeve of the suit. Better dry suit inflator valves and hoses are designed with restricted orifices. This helps prevent accidental over-inflation should the inflator valve stick. Valves with large orifices or high flow rates may freeze during ice diving. The exhaust valve on the suit should vent the suit faster than the inflator valve can supply air. Inflator valves are normally located on the chest of the suit. Inflator hoses for dry suits should only be connected to a low pressure port on your regulator’s first stage. The hose should reach the inflator valve without strain. Some inflator valves can be rotated to provide you with a choice of routing for the inflator hose (i.e., under the arm, over the shoulder, etc.). Not all inflator hoses are compatible with all dry suit inflator valves. The quality of waterproof zippers varies greatly among manufacturers. A careful comparison will assure you of reliable operation. Generally speaking, the larger waterproof zippers are the strongest. There are many options available on today’s dry suits and one of the most important is a dry hood. Much of your body heat is lost through your head. A dry hood with an insulating liner will help keep you warm under the coldest conditions. If a dry hood is used, you must remember to equalize the air space in the hood during descent by exhaling through your nose into your mask and forcing a small amount of air into the hood from beneath the mask skirt. Purge valves can be mounted in dry hoods to allow excess air to escape during ascent. Ordinary wet suit hoods can also be worn with dry suits. Other dry suit options include pockets, relief zippers (for men), and dry gloves. Dry gloves are recommended for diving in water colder than 4°C (39° F). A complete dry glove system is composed of a set of insulating liners, gloves, and rings. The inner rings are designed to fit inside the sleeve of the dry suit at the cuff. The outer rings fit over the sleeve and snap into position when properly aligned with the inner rings. The dry gloves or mittens stretch over the outer rings and are held in place by a compression fit. Dry suits generally fit quite a bit looser than wet suits, and custom sizes are available. The most critical part of a dry suit’s fit is the length. The suit should be long enough that you can bend and squat comfortably, without being too long. If the suit is too short, you will not be able to swim effectively or climb a ladder comfortably. Once you have purchased a dry suit, be sure to take the time to adjust the neck seal to your individual neck size. Latex neck seals are cone shaped and must be trimmed with sharp scissors. Neoprene neck seals must not be cut. They should only be stretched. As a rule of thumb, the circumference of the neck seal opening should be approximately 10%-15% less than the circumference of your neck. Dry suits must be carefully maintained. Latex wrist and neck seals should be periodically washed with mild FIGURE 1-29. DRY SUITS
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