Divers -especially Northwest divers- know about hypothermia. We know that we lose heat much faster in water than in air and that we need good insulation. The problem is that insulation reduces heat loss, but does not prevent it. Divers with good exposure suits still get hypothermic, but they may not realize the problem and its serious effects. This article should open your eyes to the hazards of hypothermia and make you consider even better insulation than what you are using now.

Upon immersion blood shifts within your body and makes your heart work harder to pump a greater volume of blood with each beat. Cold increases the task because your body shunts blood from the extremities to reduce heat loss. The shunted blood goes to the trunk of the body and raises blood volume above normal. Divers with marginal cardiac capability, who would not experience difficulty on land, can suffer a heart attack or acute pulmonary edema if the heart cannot react to the increased workload that results from immersion in cold water.

Another concern that arises because of complex physiological changes that occur during cold water immersion is heart rhythm abnormalities called arrhythmias. The bottom line is that your heart can stop beating and you can drown. The syndrome is called sudden death and is the cause for many unexplained fatalities. The problem seems to occur when middle age divers who are marginally fit experience a combination of cold, physical stress, and emotional stress-a situation that is not unlikely when diving.

Even divers who are fit and have healthy hearts are not immune to the effects of hypothermia. Increasing torso blood volume passes greater quantities of blood through the kidneys, which produces more urine than normal. Fluid loss reduces blood volume, but the trade-off is dehydration, which is bad because it predisposes to decompression illness. Another decompression problem is that cool blood absorbs more inert gas than warm blood. Cold blood saturated with nitrogen and trapped in extremities from peripheral vasoconstriction can cause decompression illness that would not occur if the diver had not become so cold that peripheral shunting occurred while diving. A final blood problem is that the substance thickens when cold, which further increases the likelihood of decompression illness.

Cold slowly incapacitates. It decreases sensory and motor functions. Good divers fumble with equipment and are unable to perform emergency skills because cold steals their abilities. Loss of mobility and strength also handicap the cold diver. Muscles are prone to cramping when cold. Perhaps the most insidious effect is decreased mental status, which impairs judgment. The colder you get, the less your ability to make the decision to stop diving.

A diver who is injured or suffering from profound hypothermia faces another physiological problem upon egress from the water. Exiting the water causes a rapid drop in blood pressure when the pressure on the body that causes blood shifting subsides suddenly. The normal mechanism for compensation-increased cardiac output to rapidly restore pressure-is absent because the heart is cold and unable to respond and because the blood is cold and thick. The result may be loss of consciousness with vascular collapse-an extremely serious condition. Injured divers and divers who are profoundly hypothermic must be removed from the water in a horizontal position and must minimize physical movement to avoid blood pressure problems.

Do not discount the effects of cold nor regard them lightly. There is more to cold than being miserable. Shivering in water actually increases heat loss. If you shiver when you dive, you are playing Russian Roulette with hypothermia. Insulate yourself properly. A warm diver is a much safer diver than one who is hypothermic.

Last year in my June article I promised information about stress management. It is good to start the New Year by keeping a promise. The following concepts are derived from many sources. Collectively, they provide much greater insight into stress management than nearly any of the current dive publications provide.

We begin with a definition of stress, which is the perception of a substantial imbalance between environmental demand and response capability, under conditions where failure to meet demand is perceived as having serious consequences. Stressors are conditions or attitudes that cause stress. Dive stressors, which may be internal or external, include cold, illness, exhaustion, injury, fears, equipment problems, loss of air supply, buddy separation, depth, darkness, currents, and disorientation. Stress is not always bad. Moderate stress can cause a feeling of exhilaration, improve performance, and lead to positive condition called eustress. Excessive stress causes anxiety, decreases performance, and leads to a negative condition that we call distress.

Knowledge and appraisal of a situation affect your reaction to stress. Training, experience, and your predisposition toward the situation affect your knowledge and appraisal.

Thus, your perception of the circumstances are determined by what you know and are able to do, by what you have done, and by any inherent fears about the circumstances that you might have.

The problem with stress in diving is that it can lead to panic, which is often fatal because panic is sudden, uncontrolled, irrational reaction to a perceived danger. Divers who panic often perish. We must manage stress to prevent panic. Dr. Tom Griffiths says, "the most critical factor in the progression of panic after stress increases is whether or not a problem arises."

Divers who can recognize and manage stress can overcome problems and are far safer than those who cannot cope with the effects of stress.

There are two components to stress: the physiological and the psychological. Anxiety causes involuntary physiological changes. When stressed, anxiety increases your breathing and heart rates, activates your nervous system, and decreases your awareness. These factors decrease your performance, which increases your anxiety. Heightened anxiety begins the cycle again.

Unless you interrupt the cycle, anxiety will escalate until you panic. The second component — psychological difficulty — is every bit as critical as the physical problems. Frank Pia, Chief Lifeguard, says, "Much of the distress that a person experiences when difficulty arises stems from what the person tells himself about the situation." You can be exhilarated by a situation or allow it to cause anxiety and distress. Pia continues, "The difference between panic and a heightened physiological state is the thought process."

Michael J. Asken encourages the use of Task-Relevant Instructional Self-Talk (TRIST). You determine your emotional state when in distress by what you tell yourself. Asken concludes that in a stressful situation, "Success is not achieved by focusing on the outcome, hoping for a good outcome, or even telling yourself that the outcome will be okay. The most effective self-talk involves imagining that your instructor is sitting on your shoulder guiding you through your response."

With the foregoing concepts in mind, you can recognize and manage stress. The first steps are to sense your breathing rate and your self-talk when a problem occurs. If your breathing rate is fast and you are having negative thoughts about the situation, it is time to break the stress cycle. Begin by stopping all physical activity, establishing buoyancy, and breathing deeply. (Divers in distress usually have an adequate supply of air!) As you gain control of respiration, you will be able to think more clearly. Take control of your thoughts before they take control of you. Imagine that you are telling someone else how to deal with this situation.

Assess your options, decide upon the best course of action, and then take deliberate action. As you begin to overcome the difficulty, your confidence will increase and your physiological condition will begin to return to normal.

Now you can understand why some divers are thrilled by the same situation that causes another diver to panic. Remember that stress is simply a matter of perception and that you can change your perception with training and experience. You can also learn to manage difficult situations by imagining them vividly in your mind. You body cannot distinguish the difference between an actual event and one that you imagine. As you learn to solve problems in your mind, you can learn to recognize and manage stress.

I wish you good diving and eustress.

Divers love to explore new areas. We love to see new animals and formations. We travel great distances and put in a great deal of effort to spend a small percentage of the total trip time visiting new underwater sites. Sometimes we go to such lengths to dive a new area that we dive no matter what the conditions may be. Diving when the environmental conditions are unfavorable is a leading cause of dive accidents. Since safety is a prerequisite for an enjoyable dive outing, let's examine some procedures that can help prevent accidents when you dive a new area.

A good first step to take when you plan to dive somewhere new is to learn about the place in advance. Dive site books are good, but do not rely on them completely. Contact dive businesses in the area and ask about the best seasons and times of day for diving at the selected site. Ask for phone numbers and addresses of dive clubs in the area and contact them. You may be able to join a club on a dive outing when you are in the area. Call charter boats in the area and find out about dive trips to your area of interest. When you dive from a charter boat, the Captain will provide information about the site and will know the best time to dive there.

When you arrive at your destination, take time to visit one or more local dive operations. Talk to divers about local dive sites, conditions, and hazards. See if the business has a list of divers who are looking for buddies. Write down some phone numbers and call some of the local divers who need a partner. Find someone with local experience who can accompany you. If you want a special treat, contact a local dive Instructor or Divemaster and hire one as a guide.

Plan your dives well. Make sure that your equipment is complete and functioning properly before you reach the dive site. If you had to obtain any equipment locally, such as weights and tanks, check and double-check your equipment configuration. Take weight keepers with you to lock weights in place on your weight belt. Be sure that the length of the belt is correct, that the end is not frayed, and that the quick release holds and releases properly.

Whenever you make an equipment change it is a good idea to make your first dive a simple, shallow "shakedown" dive. It is unwise to jump into deep, moving, dark water with unfamiliar, untested equipment. Dive accident studies show that dive equipment seldom fails, but that problems with equipment cause divers to fail far too often.

Another good idea for diving a new area is to "ease" your way into diving there. Gain experience gradually instead of plunging into it completely at the outset. Make night dives only at sites you have dived during the day. Attempt specialty activities such as wreck penetrations and cave diving only if you have the training and equipment that are essential for safety.

If it seems that the effort required to prepare for diving a new area is unreasonable and you are unwilling to pay for professional services, play "what if" for a minute. What if your dive is a disaster or a harrowing experience? What if you or your buddy is injured? Is it worth the risk to forego proper dive preparations? I think that you will agree that divers looking back from a terribly unpleasant experience can see what they might have done to prevent the incident. One secret to safe, enjoyable diving is to look ahead at potential problems and takes steps to ensure that dives are pleasant experiences. Looking ahead and enjoying yourself is always better than look back and wishing that you had taken the steps that could have prevented misery.

Diving new areas is great fun. I hope that you will abide by safe diving practices and reap all of the enjoyable experiences possible when you visit new dive areas.

Before the dive:

* Review entry and exit procedures with the boat crew prior to the dive. Know where and how the crew wants you to enter and where and how the crew wants you to exit. Procedures may vary with conditions.

* Review surface signals with the boat crew prior to the dive. Although signals are standard, some crews use special signals, e. g., one arm held straight up may mean "pick me up."

Surfacing after the dive:

* Get buoyant immediately when you reach the surface. Lack of buoyancy at the surface is an indication to a divemaster that you may be in trouble.

* Inflate your BC, but avoid over-inflation as it may restrict your movements or breathing. Attempting to swim face down with an over-inflated BC is difficult because the weight of your tank makes you unstable.

* Ditch your weights if you feel staying afloat is a struggle. When in doubt, get rid of your weights! Too many divers die of "lead poisoning." If you have a problem, remove your weights and hold them in your hand. If the problem becomes serious, you will automatically drop the weights. If you wait until a problem causes panic, you will not discard your weights.

* Keep your mask on and your regulator (or snorkel) in your mouth. A mask missing or on the forehead is a sign of distress. If you must breathe without a mouth-piece, roll onto your back

* If the boat is near and the crew sees you, signal that you are OK. It is frustrating for a Divemaster to signal a diver at the surface and not receive a signal in return. Failure to return a signal is another sign of distress.

* Relax/breathe normally — get comfortable with being at the surface. Look beneath the surface at other divers and you can quickly distinguish novice divers from experienced ones. The novice divers will be kicking and exerting, while the experienced divers will be relaxed and barely moving. Conserve your energy.

* Evaluate yourself. If you feel you will need to be picked up, signal the boat, but avoid waving your hands with the emergency signal. Reserve emergency signals for life-threatening situations. If you require assistance, but it is not an emergency, agree in advance on an appropriate signal, such as the raised arm previously mentioned.

Swimming to the boat:

* Three alternatives: 1) Descend to 20 feet and swim underwater; 2) swim face down; 3) swim on your back. It is easier to swim underwater than at the surface, but avoid "skimming" — swimming just beneath the surface where you cannot be seen by boaters. I prefer to swim on my back versus my stomach because I can use wider kicks and breathe easier.

* Aim for the bow of the boat. If you aim for the stern, current may take you behind the boat. Allow for drift.

* Swim as horizontal as possible. Overweighted divers overexert even when buoyant because the weight at their waist pulls their hips downward and increases their cross-sectional area. The greater the area exposed to forward motion, the greater the resistance to motion. Properly weighted divers swim level and conserve energy.

Exiting the water:

* Make sure that you are buoyant. Emergencies have occurred when divers have removed equipment for exiting without being buoyant.

* Do not move to the ladder until the diver in front of you is in the boat and has moved away from the ladder. In some cases the crew may want you to wait until they signal you. One of the worst places to be is beneath another diver on a ladder. If the diver slips or his tank or weight belt slips, you could be seriously injured.

* Keep an arm's length away from the dive platform. Upward and downward motion caused by the boat rocking can cause severe injury.

* Keep your mask on and your regulator (or snorkel) in your mouth until you are safely in the boat. Be prepared to re-enter the water unexpectedly because you may!

* Keep your fins on until you have a firm grasp on the ladder and are ready to exit. Do not let go of the boat once your fins are off! Maintain contact with the vessel while removing your fins and afterward.

* If you accidentally let go of the boat after you have removed your fins and start to drift ... tough luck, see you later (just kidding) - put your fins back on. Kicking without your fins while wearing scuba gear is ineffective.

* If the boat is not visible or is far away from you, you are:

1) screwed

2) should swim to shore

3) should start making sounds like a fog horn. (Answer: Keep reading.) If the boat is not visible or is far away:

* Do not panic. Relax and breathe normally.

* Make sure that you are buoyant.

* Prepare for this possibility before the dive by carrying surface signaling devices, practicing how to use them and review procedures prior to the dive.

* Make yourself conspicuous by using audible signals, such as whistles or air horns, or visible signals, such as safety sausages, mirrors or lights. Always remember to be prepared for the unexpected.

Proper pre-dive planning is essential for safe and enjoyable diving.