That could never happen to me, you think as you read about a swimmer being attacked by a shark. The swimmer, of course, probably thought the same thing. The situations that follow may seem far-fetched, but they've happened before and they'll no doubt happen again. As the Boy Scouts say, "Be prepared."

What to Do If Your Parachute Fails to Open
1. As soon as you realize that your chute is malfunctioning, signal to a companion whose chute has not yet opened by waving your arms and pointing to your chute.
2. When your companion (and new best friend) gets to you, link arms.
3. Once you are hooked together, the two of you will still be falling at terminal velocity, or about 130 miles per hour. When your friend opens his chute, you will not be able to hold on to each other normally, because the G-forces will triple or quadruple your body weight. To prepare, hook your arms into his chest strap, or through the two sides of the front of his harness, all the way up to your elbows.
4. Open the chute. The shock will be severe, probably enough to dislocate or break your arms.
5. Steer the canopy. Your friend must now hold on to you with one arm while steering his canopy (the part of the chute that controls direction and speed). If your friend's canopy is slow and big, you may hit the ground gently enough to break only a leg. If his canopy is a fast one, however, your friend will have to steer to avoid landing too abruptly.
6. If there's water nearby, head for that. Once you hit the water, you will have to tread with just your legs and hope that your partner is able to pull you out.

How to Fend Off a Shark
1. Fight back. If a shark is coming toward you or attacking you, use anything you have in your possession—a camera, your fist—to hit the shark's eyes or gills, the areas most sensitive to pain. (Contrary to popular opinion, the shark's nose is not the area to target.)
2. Make quick, repeated jabs in these areas. Hitting the shark tells it that you are not defenseless. A shark will usually follow through on an attack only if it has the advantage, so making it unsure of its advantage in any way possible will increase your odds of survival.

How to Escape from a Sinking Car
1. As soon as you strike the water, open your window. This is your best chance of escape, because outside water pressure will make the door very difficult to budge. (To be safe, you should keep the windows slightly open whenever you are driving near water or on ice.) Opening the windows allows water to come in and equalize the pressure. Once the water pressure inside and outside the car is equal, you'll be able to move the door.
2. If your power windows won't work or you cannot roll your windows down all the way, attempt to break the glass with your foot or shoulder or a heavy object such as an anti-theft steering-wheel lock.
3. Vehicles with engines in front will sink at a steep angle. If the water is 15 feet or deeper, the vehicle may end up on its roof, upside down. For this reason, you must get out as soon as possible, while the car is still afloat. Depending on the vehicle, floating time will range from a few seconds to a few minutes. The more airtight the car, the longer it floats. Air in the car will quickly be forced out, and an air bubble is unlikely to remain once the car hits bottom.
4. If you are unable to open the window or break it, you have one final option. Remain calm, and wait while the car begins filling with water. When the water level reaches your head, take a deep breath and hold it. At this point the pressure should be equalized inside and out, and you should be able to open the door and swim to the surface.

How to Fight a Mountain Lion
1. Do not run. The animal will most likely have seen and smelled you already, and running will simply cause it to pay more attention.
2. Mountain lions are less likely to attack a larger animal, so try to make yourself appear bigger by opening your jacket wide. Hold your ground, wave your arms, and shout. Do not crouch.
3. If you are with small children, pick them up—do all you can to appear larger. Children, who move quickly and have high-pitched voices, are at greater risk than adults.
4. Back away slowly, or wait until the animal leaves.
5. If the lion still behaves aggressively, throw stones. Convince the lion that you are not prey, that you may in fact be dangerous yourself.
6. Most mountain lions are small enough that an average-size human will be able to ward off an attack by fighting back. Hit the mountain lion in the head, especially around the eyes and mouth. Use sticks, fists, feet, or whatever is at hand. Do not curl up and play dead.
7. Protect your neck and throat at all costs. Mountain lions generally leap down upon prey from above and deliver a "killing bite" to the back of the neck, but they will also rush and lunge up at the neck of prey, dragging the victim down while holding the neck in a crushing grip.

How to Jump from a Bridge into a River
When attempting a high fall (more than 20 feet) into water in an emergency situation, you will not know much about your surroundings, specifically the depth of the water.

If you're jumping into a body of water with boat traffic, try to land in the channel—the deep area where boats go under the bridge. (It's generally in the center, away from the shoreline.) Steer clear of any pylons that are supporting the bridge, since debris tends to collect in these areas.
1. Jump feetfirst. Don't even think about going in headfirst unless you are absolutely sure that the water is at least 20 feet deep. If your legs hit bottom, they will break. If your head hits, your skull will break.
2. Keep your body completely vertical. If your body is not straight, you can break your back upon entry.
3. Squeeze your feet together.
4. As you enter the water, clench your buttocks to prevent water from rushing in and causing severe internal damage.
5. Protect your crotch by covering it with your hands.
6. Immediately after you hit the water, spread your arms and legs wide and move them back and forth to generate resistance, which will slow your plunge. Always assume the water is not deep enough to keep you from hitting bottom.
7. Swim to shore immediately after surfacing.

How to Escape from Quicksand
Quicksand is just ordinary sand mixed with upwelling water, which makes it behave like a liquid. But quicksand—unlike water—does not easily let go. If you try to pull a limb out, you have to work against the vacuum left behind. Because you are more buoyant in quicksand than you are in water, however, floating is relatively easy.
1. When walking in quicksand country, carry a stout pole.
2. If you start to sink, lay the pole on the surface.
3. Flop onto your back on top of the pole. After a minute or two, equilibrium will be achieved, and you will no longer sink.
4. Work the pole under your hips, at a right angle to your spine. The pole will keep your hips from sinking as you (slowly) pull out one leg, and then the other.
5. Take the shortest route to firmer ground, moving slowly.

How to Run from Killer Bees
The Africanized honeybee is a cousin to the run-of-the-mill honeybee that has lived in the United States for centuries. The "killer bee" name was created after magazine reports of several deaths that resulted from Africanized-bee stings some years back. Africanized honeybees are considered "wild"; they are easily angered by animals and people.

Bees swarm most often in spring and fall, when the colony migrates to establish a new hive. They may move in large masses until they find a suitable spot. While any colony will defend its hive, Africanized bees do so with gusto. (Regular honeybees will chase you about 50 yards; Africanized honeybees, three times that distance.) These insects present a danger even to those who are not allergic.
1. If bees begin flying around you or stinging you, do not freeze. Run. Swatting at them only angers them.
2. Get indoors as fast as you can. If no shelter is available, run through bushes or high weeds. This will help give you cover.
3. Do not jump into water. Bees are likely to be waiting for you when you surface.
4. If a bee stings you, it will leave its stinger in your skin. Remove the stinger by raking your fingernail across it in a sideways motion. Do not pinch or pull the stinger out—this may squeeze more venom from it into your body. Do not let stingers remain in the flesh, because venom can continue to pump into the body for up to 10 minutes. (If you think you might be allergic, see a doctor immediately.)

How to Survive When Adrift at Sea
1. Your best chance is on a boat, even a disabled one, so stay aboard as long as possible.
2. Get into the life raft, and take whatever supplies you can carry—most important, any water in jugs. A person can last for a while without food at sea, but without clean drinking water, death is a virtual certainty within several days. If worst comes to worst, throw the jugs overboard so you can pick them up later—they will float. Many canned foods are packed in water, so take those if you can. Do not skimp on water; drink it as needed (a half-gallon a day should be sufficient if you limit your activity). Do not drink seawater.
3. If you're in a cold water/weather environment, keep warm. You are more likely to die of hypothermia than of anything else. Put on dry clothes and stay out of the water. Prolonged exposure to salt water can cause skin lesions, which are prone to infection. Stay covered: modern rafts have canopies, but if the canopy is missing or damaged, wear a hat, long sleeves, and pants to protect yourself from the sun.
4. Find food, if you can. Life rafts include fishing hooks in their survival kits. If your raft is floating for weeks, seaweed will grow on its underside and fish will naturally congregate in the shade under you. You can catch them with the hook and eat the flesh raw. If no hook is available, you can fashion one using wire or even shards of aluminum from an empty can.
5. Try to reach land, if you know where it is. Most rafts include small paddles, but in any wind above three knots you'll find it hard to maneuver. Be careful not to exhaust yourself.
6. If you see a plane or boat, try to signal with a radio or flare, or by flashing a mirror.

Excerpted from The Worst-Case Scenario Survival Handbook by Joshua Piven and David Borgenicht, to be published in November by Chronicle Books.

By David Borgenicht and Joshua Piven