Why Dive Dry

BASIC DRYSUIT SKILLS

Adding air to your drysuit

You press the center of the inflate valve (generally located on your chest) to add air, just as you would press the power inflate button on your BC. This means you will have another low-pressure hose, connecting to the suit’s inflator valve, and your first stage will need to have a spare port for it. Venting air from your drysuit You can vent air from your drysuit by pressing the center of the exhaust valve (generally located on your upper left arm). The valve is located at the highest point on the suit to vent all the air, so the technique is to raise your left shoulder and elbow. It works best from a vertical position, your normal ascent posture. Most exhaust valves today also vent automatically. Rotating the valve body adjusts the pressure at which the valve starts to dump air. Tightened all the way (rotated clockwise), the valve only dumps manually. Loosened all the way (rotated counter-clockwise) it dumps when pressure in the suit is just a little over the ambient pressure. This actually makes ascent control easier because if you loosen the valve all the way it will maintain neutral buoyancy for you as you ascend. That leaves both hands free—one to hold your console, for example, and one to hold an ascent line. Just remember to raise your left elbow. One caution: Most exhaust valves do not dump air as quickly as will the best BCs do, and the valve can become clogged by fibers from your clothing. You need to be aware of your buoyancy so you never get very positive, because once an uncontrolled ascent starts, it can be difficult to stop with the exhaust valve alone. In an emergency, you can vent air much faster by opening a wrist seal or your neck seal with a finger. Water may enter, so you don’t want to make this standard practice, but opening a seal might be necessary to stop a runaway ascent. In a shell-type drysuit you can even regain neutral buoyancy if you lose your weightbelt, by flooding the suit. That’s something you can’t do in a wetsuit. Correct weighting Adjusting your weighting for the smallest amount of ballast is especially important for diving dry because extra lead requires extra air in the suit to achieve neutral buoyancy, so you have a larger air bubble moving around in the suit and disrupting your trim. Your goal should be to dive with the minimum amount of air in the suit, therefore the minimum amount of weight on your belt. For warmth, all you need is enough air to maintain most of the thickness of your undergarments. That’s not much. Minimizing the air in the suit is easy. After putting the suit on and closing the waterproof zipper, put your finger underneath the neck seal. Then crouch down and hug yourself to force the air out of the suit. Remove your finger and stand up. You are now vacuum packed! Note: If you are properly weighted, when under water, lift your arm above your head. All of the air in your suit will go into your arm. Depending on your size, you should have an air bubble that goes from your wrist to about mid-forearm. For larger divers, it could go as far as your elbow. But that’s it! Do You Need To Take A Class? That's your call. Nobody is going to ask to see your drysuit C-card, but a class certainly doesn't hurt, especially if you're worried about diving dry. You'll get help with proper weighting, learn specific techniques like stopping an out-of-control ascent and recovering from a foot-buoyant position. You'll also pick up tips on suit maintenance and easy dressing. You'll also have the advantage of an instructor observing your technique, correcting it and the opportunity to practice it until you get things right. So why wouldn't you take a class? A second option is an experienced and patient buddy who wants to act as your personal instructor, though the risks of an amateur instructor are, obvious. In either case, practice makes perfect. Get some pool time in a suit and practice the various skills before you head out to dive.