Dangers to Survivors

Principles of Survival at Sea

Principles of Survival at Sea

An overview of the course, concepts and definitions. We will also go through different emergency situations and precautions.

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Evacuation and Rescue

Evacuation and Rescue

What to think of when abandoning a vessel, rescue equipment and what life saving-appliances you will find onboard.

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Survival at Sea

Survival at Sea

How to manage the dangerous situation after abandoning the vessel and what you can do to increase your chance to survive.

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Communication During Emergency and Rescue

Communication During Emergency and Rescue

Different radios and how they work and how to communicate as well as act during a helicopter rescue.

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Step 1 of 113 minutes read

Dangers to Survivors

After an "abandon ship," the survival craft and its crew are exposed to several dangers and action has to be taken from the start to minimise the chance of injuries. Examples of dangers are heatstroke, sunstroke, exposure to cold and hypothermia. Effects of seasickness are also a danger and it can lead to a failure to maintain body fluid correctly, causing dehydration. Other hazards are drinking seawater, fire or oil on water and sharks.

In clear weather, an aircraft can spot a lifeboat from 8 km away. Photo: Sjöfartsverket

When abandoning a ship, it is vital to clear away from the vessel quickly. If the survival craft is not equipped with an engine, use the oars or paddles to manoeuvre clear from the yacht and keep clear of floating obstructions, which may damage your survival craft.

Heat Stroke, Sun Stroke, Exposure to Cold and Hypothermia

In warm or tropical climates, excessive exposure to the sun and heat can cause terrible cases of sunburn and hyperthermia (or heatstroke). The effects of heatstroke are similar to hypothermia except that, in this case, the body cannot lose heat fast enough. The body core temperature rises and eventually affects the nervous system leading to unconsciousness and possibly death. You must, therefore, protect yourself from the heat by turning the life raft entrances into the wind to allow a breeze through the craft. This can be done by altering the position of the drogue attachment to the raft by pulling the drogue line around near the entrance and making it fast. 

You should also wet your clothing early in the day and allow the heat to dry it out. Contrary to popular belief, cover as much of the body with clothes as possible rather than being naked is cooler. Ensure the garments are dry by nightfall when relatively much lower temperatures can be expected, even in the tropics. Do not move about more than necessary; it will just make you hotter. Splash or spray water on the exposure cover or liferaft canopy. Occasional small sips of water or even damping the lips are beneficial during the day. Never use salt water for this purpose.

Seasickness

Most people, even experienced seamen, suffer from seasickness in survival craft. This results in a loss of body fluid and incapacitation. Seasickness tablets should be taken by everyone as early as possible. This medicine is included in the liferaft equipment box.

Dehydration

Regular loss of water from the body each day is at least 1 litre when neither food nor water is taken. A human body consists of about 60% water or for a person who weighs 70 kg, about 40 litres of water, of which 25 litres must be maintained for life to continue. In theory, a person would, therefore, survive for at least 10–14 days if there was no additional loss of water and longer with the availability of the water rations supplied in the craft.

Accelerated Water Loss

Several things will cause an accelerated water loss from the body. It can be sweating due to exertion or heat, vomiting or diarrhoea. Urine contains poisonous waste products that the body has discarded. It is no use and urine must not be drunk. Neither should seawater. The salt in seawater must be dissolved using water from the body so that the kidneys can pass the salt into the urine. This sets up a vicious circle - the more saltwater is drunk, the more freshwater is taken from the body cells to dissolve the salt. Continued drinking of seawater is fatal. 

Eating or sucking fish, sea birds or seaweeds are not beneficial for the hydrations of the body. They are salty to a greater or lesser degree and seaweed should never be eaten unless extra water, at least 1 litre more than the ration, is available. Fish and birds are also salty and require additional freshwater to be drunk. The spinal fluid of fish contains freshwater and can be safely sucked out and drunk.

Fire or Oil on Water

As a result of an accident, oil might be present on the water surface. This could harm the survivors if heat or open flames occur, which could ignite the oil and be a significant risk for the survival crafts in the area. Survivors who have spent time in the water which has been contaminated by fuel oil are likely to be affected by severe problems. The person in the water may swallow the oil, get it on the skin, the oil can pollute the lungs or cause inflammation in the eyes. Consuming fuel oil usually causes vomiting and its effect will wear off in a few days. Milk or additional water should be given to replace body fluid lost due to vomiting.

Oil on the skin should be cleaned off as far as possible. The skin is unable to perspire or breathe and can be the cause of death if the patient is smothered in oil. 

Little can be done in the craft for a patient who has polluted his lungs with fuel oil. It can be dangerous and lead to pneumonia. Rest, warmth and fresh air are about the only treatment. If there is an inflammation of the eyes, the eyes should be washed out and protected from bright sunlight until the inflammation has gone.

Sharks

If in shark-infested waters, survivors are advised to bind up any bleeding or open wounds before entering the water and then to keep perfectly still. It is stated by one authority that persons are better protected if they can remain inside a plastic bag. All life rafts are equipped with a basic fishing tackle. However, it shall not be used if sharks are near and all fishing to be ceased if one appears.

Reduce Drift

Launch a sea anchor or drogue when clear of the vessel to reduce the rate of drift. Try to remain in the immediate area of the abandoned yacht - remember this is the last location that the search parties will have

When gathered together, survival crafts should be made fast to each other. About 10 meters distance is generally sufficient to allow for wave action. Prevent craft snatching or pulling unduly on the lines to avoid damaging the attachment points or even overturning inflated rafts. The drogue on life rafts also holds the entrances across the weather and steadies the raft.

Duties of a Lookout

Post a lookout, with frequent changes, so they do not get too cold or too much sun exposure. The immediate duties of the lookout are to listen for whistles or cries for help, look for other survivors in the water, signalling lights and lights of other rafts, ships or aircraft. The lookout should also report the presence of any immediate dangers or debris which could be of use. Watches should be set in pairs for about one hour at a time with one person on the outside lookout and the other on watch inside the liferaft.

Duties of the Watch Inside the Raft

The person on the inside is responsible for supervising the raft management while others rest. This includes attending to the injured, collecting rainwater and looking after equipment & valuable items.

How to Increase the Chance of Being Detected by Others

Do not attempt to sail away from the area of the sinking vessel. As stated before, the search for survivors will commence at the last known position of the yacht. Survival craft should be kept together to provide a bigger location target. There will also be more survival aids to share. Where a survival craft portable radio is available, ’distress’ messages should be transmitted, following the simple instructions provided on the equipment. Rescuers can ’home in’ on these signals. Distress flares and rockets should be used only when a potential rescuer is likely to be in the vicinity or can be heard or seen. 

Avoid the use of flares and rockets when helicopters are in the vicinity, this may blind the pilot. Alternatively use a smoke signal.

If the sun is shining, the heliograph can be used to attract attention. If you are sighted by a searching aircraft, it may be some time before rescue is at hand, but your location will be known. From the air, on a fine sunny day, the maximum distances a lifeboat or liferaft are likely to be sighted are 8 km and 5 km, respectively. Slightly less from a searching ship. These distances will be considerably reduced in bad weather or poor visibility. To attract the attention of search aircraft and ships, the ranges of visibility will be extended by the use of the signalling equipment onboard the survival craft. The signalling equipment onboard and methods are described in the following paragraphs.

Equipment and Methods for Detection

There is radio equipment up to 100 km. At night, there are rockets with 20-30 km reach and hand flares up to 10 km. During the day, you can use the orange smoke signal. It has up to 10 km reach. Lights on liferafts can be visible up to 3 km. Exposure covers and canopies are designed to be highly visible and can be spotted up to 8 km in fine weather. A retro-reflective tape will reflect the light of searchlights from ships or aircraft – keep it clean!

The reflected sunlight from a heliograph mirror can be seen up to 30 km in good conditions. In bright sunshine, it is probably one of the most effective visual signals available. Instructions for the use of a signalling mirror are included with the equipment in the survival craft.

The whistle provided in survival craft and on lifejackets may prove invaluable in poor visibility and has a better range than the human voice. The signalling torch for use at night has a reach of about 5 km. A flashing light is more likely to be sighted, such as repeated flashing of the Morse signal SOS.

Morse SOS signal – Use a flash light and repeat the morse signal SOS.

Maintaining Morale

It is essential for morale that survivors should be kept busy and their minds occupied consistently by reducing physical exertion to a minimum. Duties to be carried out while waiting for rescue can be lookout and care of injured, craft maintenance and emptying of water to keep raft dry. Other duties can be navigation, maintaining records and so on.

Shark Repellents

A shark repellent is any method of driving sharks away from an area, object, person or animal. One type of shark repellent is BCB, which contains crystalline acetate and a thick black dye that repels and disorientates sharks. When this foil packed sachet is squeezed in water, the crystalline acetate produces a dense black cloud. The inner bag has an attachment cord so it can be kept close to your body. Means of survival if in water and not in lifeboat or liferaft. If you end up in the water, there are different positions that you can use to increase your chances of survival. If you are more than one person in the water - help each other!

By floating in the Heat Escape Lessening Position, you reduce exposure to the water. The position looks almost like sitting. Bring your arms close to the side of your body, cross your ankles, keep your legs closed and pull up your knees. Hold your hands underneath the knee joints and protect the groin. Illustration: Annika Modigh/Bridget.

If there are more persons in the water, the Huddle position might help in some cases, with moral, injured persons, etc. Wrap your arms around each other, form a circle facing the others, and keep your bodies as close as possible together. Fill up the inner circle, and try not to move. The HUDDLE position reduces heat loss by limiting the body's surface exposed to the water and helps search and rescue (SAR) units in locating you. Illustration: Annika Modigh/Bridget.

If there are no lifesaving appliances nearby and you are with several persons in the water, the best option is the survival circle. You have to hook in your arms and put your legs into the middle. The last two persons on either end of the row will have to swim to each other to make it a full circle. This circle turns a group into a bigger spot and is, therefore, easier to detect by any SAR unit. You also have a 360° view so you can keep up the morale by telling jokes and you can spot any rescuers from any direction. Illustration: Annika Modigh/Bridget.

When you are with more people in the water, and you have to swim, you can "Crocodile." Instead of crossing your legs, you put your feet in the armpits of the next person. The last person in the line will lay on his belly between the legs of the second last person so he can give instructions. This method is of great help if you have to transport any casualties. But remember swimming is always your last option. Illustration: Annika Modigh/Bridget.

If You Have to Swim Alone

If you have to swim, then do this in the least energy-consuming way. Note that swimming cools you down extremely fast, so only swim short distances e.g., to a life raft. The most efficient method is to turn yourself on your back, cross your legs at the ankles and paddle evenly with your arms. Now and then, look behind you to see where you are going.

Hopefully, none of these scenarios will happen to you. But it's important to imagine yourself in a situation of emergency and memorise what's your responsibility and have a basic understanding of the dangers and what to do to survive.