Sea Survival in Cold Climates

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Basic skills and procedures are similar in most survival locations. In colder regions, however, where extremely low air and water temperatures prevail, specialized skills and equipment are necessary.

The ability to stay warm in areas of extreme cold is of paramount importance. The capability to regulate and conserve your body heat may mean the difference between life and death. This is not based as much on skill and ingenuity as it is on having the proper equipment and the knowledge of how to use it.


The regulation of body heat loss is a primary concern in cold climates. The type of clothing you wear is one of the most important factors influencing heat loss.

You must wear proper clothing that will trap a narrow layer of air next to the skin. This zone of air is warmed by the heat generated from the body, and your clothes serve as an insulator to retain this warm air.

Materials such as animal fur, down, and wool are made up of thousands of tiny air pockets. They efficiently produce a “dead air” zone next to the skin. Several layers of clothing are usually more effective in retaining and controlling heat than a single, bulky garment.

Exposure to wind and wetness will affect the efficiency of the warm-air zone under your clothes. Wet clothing and cold wind will transfer the heat out of this zone faster than the body’s heat generating system can replace it. This exposes you to the dangers of hypothermia. If clothing becomes sopping wet it should be re moved, wrung out and only worn again if no dry clothes are available.


When cruising in cold climates have a survival suit for each crew member. These suits are made of highly efficient insulating materials and will enable you to withstand cold temperatures far better than regular clothing. There are many types of survival suits available to the consumer, from well flotation jackets to actual dry suits that provide complete protection by totally sealing out the water (Figs. 9-1 and 9-2).

Fig. 9-1 Being properly equipped with a survival suit can greatly extend Survival time in cold waters. (Photo courtesy Survival International Inc.)

Fig. 9-2 Survival Suit. (Photo courtesy STEARNS)

A neoprene vest or wetsuit in your provisions can serve as a practical piece of gear. They provide insulation and protection from the elements and are efficient as an alternative in an emergency situation. It should be noted, however, that wearing a wetsuit can cause unwanted perspiration and may not be advisable.

Figure 9-3 shows a U-Vic Thermofloat jacket. This design has protective qualities for guarding against hypothermia.

Fig. 9-3 U-VIC Thermo Floatation Jacket. (Photo courtesy Mustang)


The possibility of losing too much body fluid and causing a state of dehydration can be a serious problem in cold climates. If the water ration is low, dehydration can begin its harmful effects on the body, and only the intake of water can remedy it. Furthermore, during strenuous labor in cold climates the body may perspire a lot, but the victim will not feel the natural thirst for water as he would in hot climates. Consequently, he may not feel inclined to replace the lost body fluids, and this can seriously contribute to dehydration.


There are a number of physiological complications that can arise as a result of exposure to severe cold. The unique characteristic of survival in severe cold climates is that the initial actions you undertake must be the correct ones and must be taken immediately. This is extremely important because cold and freezing temperatures can adversely affect the body rapidly. The foremost danger, of course, is that of freezing to death.

Review and understand the following maladies and physiological processes to know how to minimize their dangers in cold climates:


Hypothermia occurs when the temperatures within the central body core reach a subnormal level. When the core temperature drops below 90°F (approx. 32°C) serious complications begin to develop and death may occur when the core temperature drops to 80°F (30°C).

In the unfortunate event of cold water immersion, remember some additional points concerning hypothermia:

• If you are wearing a flotation device, less body heat will be lost by remaining still in the water rather than swimming or treading water. Curling up into a fetal position can increase your survival time.

• About 50% of your body heat is lost from the head area. When immersed try to keep your head as far out of the water as possible.

• If there are several people in the water, huddling close together can help preserve body heat.

• Even if a person appears dead from hypothermia or cold water drowning, continue artificial ventilation and circulation as long as possible. When a person falls into water with a temperature of 70°F or less, an involuntary response called the mammalian diving reflex might be triggered. This reflex automatically shuts down the flow of oxygen to all but the most vital areas—the heart, lungs, and brain—sustaining life for remarkable periods of time without breathing. In one case a college student survived without ill effects after being submerged for 38 minutes.


Frostbite is an ever present danger in freezing temperatures. It affects the extremities of the body first. Its onset and symptoms are often difficult to detect. Familiarize yourself with both the symptoms and prevention of frostbite, which are covered in depth in Chapter 10.

Immersion Foot

Immersion foot occurs as a result of prolonged exposure of the lower extremities to waters just above freezing temperatures. Since it is difficult to keep water out of the life raft, immersion foot is a constant threat in cold water climates. The symptoms and prevention of immersion foot are covered in Chapter 10.

Snow Blindness

Snow blindness is caused by brilliant reflections and glare off of snow and ice. It can occur even on cloudy days and is very painful and debilitating. Symptoms include:

• A loss in the ability to detect the horizon (differentiating between land’s horizon and the sky)

• A burning sensation in the eyes

• Pain, which can be felt when the eyes are exposed to even the weakest light

Prevention is the best medicine; but complete dark ness is the best available cure once a person is stricken with snow blindness. Prevention can consist of wearing sunglasses or some other type of eye shade. You can improvise with wood or leather by making a narrow slit for each eye and wearing them as you would sunglasses (Fig. 9-4). This reduces the amount of glare entering the eye. Black soot applied to the nose and cheeks will also help to reduce glare.

Fig. 9-4 Eye shades can be improvised to protect the vision from sun glare.


It is possible to get a severe sunburn even on cloudy days. It is best to prevent sunburn before the need for treatment arises. If possible, leave no part of the body exposed. Be attentive to those who are asleep or ill, and make sure their bodies are protected from the sun. Sun burn can come on gradually and may go unnoticed until it is too late.

Carbon Monoxide (CO) Poisoning

In close, closed quarters where fire is used to produce warmth, carbon monoxide poisoning can be a danger. Any use of fire, even with heaters or lamps, can produce a dangerous amount of odorless carbon monoxide fumes that can be fatal. Proper ventilation will prevent this type of poisoning.


Icebergs are constantly melting and repositioning themselves. The melting process is faster below the water line than it is above the water line. Consequently, icebergs become top heavy and topple over, creating peril for any thing and anyone nearby. Avoid icebergs that are pinnacled. For shelter, seek out low, flat ice-bergs.



Almost all freshly caught sea fish are edible and nutritious when eaten raw. Since cold climates act as refrigeration, fish are less susceptible to spoilage than in warmer climates. A fish can be effectively preserved by slicing it into thin strips and hanging it to dry.


Most large arctic mammals, such as seals and walruses, are difficult to approach and will generally avoid man. Because of their large size, most are capable of inflicting injuries and should be approached cautiously. Almost all marine mammals are a viable food source if they can be caught. The liver, especially in arctic and cold-water mammals, should not be eaten because of their frequent toxic concentrations of Vitamin A.


Sea birds can be used for food. Fresh eggs are edible at any stage of embryo development.


• Always melt snow before consuming it. The body heat required to melt snow in the body after it has been consumed may be too valuable to waste. Snow may be melted by holding it in your hands, if conditions permit. (Watch for the onset of frostbite.)

• Melt ice rather than snow. Ice will yield more water per volume, and it requires less heat and time to melt.

• Sea ice loses its salt content after approximately one year, then it becomes an excellent source of water. “Old” sea ice can be distinguished by its bluish color and rounded corners. Newer ice that still contains salt will appear grayish, milky, and hard. Do not drink it.

• The salt can be removed from sea water in freezing climates by the following method: Collect seawater in a container and allow it to freeze. Fresh water freezes first and thus the salt will concentrate as a slush in the center or core of the container. Remove this core of salt, re-melt the ice, and it will be sufficiently salt free to keep you alive.


Icing at sea can present a serious hazard to smaller ships and vessels. The added weight of ice reduces the range of a vessel’s stability, particularly when icing occurs on the masts, rigging, and superstructure. Vessels may become top heavy and capsize. The accumulation of ice on aerials can render radar or radios inoperative.

Freezing Rain

Freezing rain can cover a ship with a fresh-water glaze of ice. This accumulated weight of ice is unlikely to directly endanger a ship.

Arctic Frost Smoke

Arctic frost smoke or white frost occurs in temperatures below 32°F. Small water droplets in the frost smoke are super-cooled. Part of the droplet freezes immediately when contact is made with a craft. The result is an accumulation of white “rime” ice. (It is easier to remove rime ice than clear ice or glaze because it is porous.)

Freezing Spray

The most dangerous form of icing is freezing spray. It occurs when the air temperature is below the freezing temperature of sea water (27 °F). Spray freezes on ex posed surfaces to produce clear ice or glaze. The lower the air temperature and the stronger the wind, the more rap- icily ice will accumulate.

It must be understood that as ice forms on areas that are exposed to spray (such as the rails and rigging), the affected surface area increases in size allowing for an even greater and rapid accumulation of ice.


Breathing. In severe cold temperatures, breathe only through your nose. This helps to warm the air before it reaches your lungs and will lessen the danger of frosting them.

Navigation. In polar regions, a magnetic compass may not be as reliable as in other areas. The compass may react sluggishly and inconsistently. It is advisable to take the average of several readings in order to increase accuracy.

Blood. Blood is affected by cold temperatures. It may take longer to clot and will appear to be thinner.

Urine. Urine can be a source of heat, if necessary. If, for instance, your body touches a frozen metal object, it may freeze onto it. Forcibly removing it may cause tearing of the skin. Urine can act to thaw the part so that it can be safely removed.

Exposure. Be careful not to expose more of your body than is necessary (such as for bowel movements).

Body Heat. Huddling together can help contain and share body heat, but take care not to promote hypothermia in your own body by warming a wet or frostbitten victim.

Landfall. In the arctic regions, snow-covered land areas or large ice fields are often indicated by light colored reflections on clouds. This is markedly different from the normal darkish gray reflection caused by open ocean.

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