Capsizing, Sinking And Falling Overboard (1968)

[Music] The three major causes of loss of life in pleasure boating accidents are capsizings, sinkings, and falls overboard. Of annual fatalities, capsizings account for more than 47% or over 600 lives. Many of these lives might be saved if boatmen knew and remembered a little bit of how and why their boats float, and a few things to do or not to do to keep them afloat. A good place to start is with an understanding of the very basic principle of buoyancy as it applies to the average pleasure boat. Buoyancy is the upward force exerted upon an immersed body by a fluid. Buoyancy is what makes a boat float. As an empty boat is placed in the water, a buoyant force is exerted on the hull to keep it afloat at the depth where it has displaced a volume of water equal to its own weight. At this point, the force of buoyancy is equal to the force of gravity. If weight is added to the boat, it settles deeper into the water until the force of buoyancy and the force of gravity are once again equal. As the load forces a boat deeper into the water, the freeboard or hull area above the waterline is reduced. Overloading can cause the freeboard to be reduced to the danger point. Every boat, large or small, has a safe load capacity. This is the point where the forces of gravity and the buoyancy are equal with enough freeboard left for safe operation. The buoyant force which makes a boat float also attempts to keep it stable and upright. When a boat is properly loaded with the weight evenly distributed, the buoyant force is exerted equally on the underwater surfaces of the hull. Unbalance the load and the buoyant force shifts to resist the unbalanced condition attempting to keep the boat from capsizing. Unbalance the load still more and despite the buoyant force, stability is decreased and freeboard reduced dangerously on the heavy side of the boat. In this condition, a boat can very easily be capsized. Proper fore and aft balance should also be maintained in a boat. Poor longitudinal distribution of weight can also result in loss of stability and reduce bow or stern freeboard to the danger point. The stability of a boat can also be reduced by poor vertical distribution of an otherwise safe load. The basic rule is the higher the load, the less the stability. Like standing up in a rocking chair. This rocking chair effect can rock you right into the cradle of the deep if you aren't very careful. Remember the old familiar cry of "Sit down. You're rocking the boat." Stability of a boat is also directly related to the waterplane area. This man moving too far forward in a small boat is working against the small waterplane area under the narrow bow. Moving his weight to the stern of the boat, he's working against a much larger waterplane area under the wide stern section of the hull. Another factor contributing to capsizing is water in the boat. This loose water, as it is commonly called, may be a result of leaks, rainfall, or spray taken aboard in rough water operation. Under static conditions, loose water is simply added weight which reduces freeboard. However, when any outside force, such as rough water, maneuvering or shifting of a load causes the boat to list, the water runs to the low side and further reduces freeboard and stability. Unlike solid weight, loose water continues to shift and prolong the unstable and often unsafe condition. Always remember, no matter what size or shape, boats have greater stability when they are not overloaded, when they are free of loose water, and have their proper load evenly distributed low in the hull. Observe these basic rules and you probably won't be one of the almost 700 boatmen each year who find out about capsizing the hard way. [Music] In addition to capsizings, sinkings cause a great loss of life in boating accidents. Average figures show that more than 100 lives are lost in this manner each year. Enough water to sink a boat may be taken aboard in many ways, most of which can be prevented by a safety-conscious boat operator. By spray or water coming aboard from running too fast in rough water, or by poor distribution or shifting of weight in a boat resulting in loss of freeboard on one side. It doesn't take a crowd. One or two people can create a potential sinking situation in a small boat. Enough water to cause sinking can also be taken aboard through failure of the hull structure by damage or deterioration, starting of a plank, holing, poor caulking, or unswelled planking. In rough weather, caulking may be driven out by pounding or vibration while underway, especially at high speed. Failure of fittings may also result in taking excess water into the boat. A defective cooling hose, faulty piece of pipe, or broken plumbing fitting, a loose rudder post, or shaft log that's lost its packing. Even water back siphon through the exhaust of an inboard engine. Taking on water doesn't necessarily mean loss of the boat by sinking if prompt action is taken. Emergency repairs to stop the intake of water followed by several methods of dewatering will often keep a boat afloat until safety of the beach or of a dock can be reached. The best method of dewatering is adequate power operated pumps, but in their absence, hand pumps will do the job. There are also any number of different hand bailers available. Some of commercial design, others which can be improvised in an emergency. Even if the boat isn't in danger of sinking, excess water should be removed for safe operation since such loose water reduces stability. Remember, sinkings account for loss of over 100 lives each year. The third major cause of fatalities in pleasure boating is falls overboard. Whoops. Almost missed that one. Let's see it again. Now, as we were saying, falls overboard are a major type of pleasure boating accident taking more than 300 lives each year. Over half of these falls are caused by loss of balance due to wave action, slippery decks, or unexpected moves of boat or other passengers, or any combination of these causes. Many other falls overboard result from careless or reckless boat operation. Of boat operators not checking to make sure that all persons are properly seated before getting underway. Falls overboard are also caused by irresponsible or reckless boat handling. The all too familiar water cowboy going too fast in rough water, making violent, unnecessary maneuvers, and sudden stops or starts. Some of this irresponsible operation can be attributed to intoxication. Improper handling or lifting of heavy objects in a boat or alongside the dock contributes its share to falls overboard and in many instances loss of life. Like all other types of boating accidents there are simple but effective preventative measures and precautions which can be taken to keep falls overboard to a minimum. Beware of slippery decks. Keep low and well-balanced when working or lifting heavy objects and be careful and considerate of the other fellow. Avoid standing up in small boats except when necessary. Move about carefully and stay to the center line of the boat as much as possible. Whether standing or sitting always try to anticipate any sudden move of the boat whether it be from rough water maneuvering or the wake of another boat. In spite of best efforts and intentions someone may fall overboard from your boat or one nearby. So, always be prepared. One of the best safety precautions is to teach all members of the family to swim. Swimming is not only fun but provides an extra margin of safety just in case. You may never need that extra margin of safety or wind up like this if you remember the fundamentals of how and why a boat floats and some of the ways to keep it that way. The most basic of these fundamentals is the force of buoyancy. The force that keeps a boat afloat. Added weight forces a boat deeper into the water reducing freeboard as it goes. Add enough weight and you'll eventually sink even if the weight is properly distributed. You can hasten the capsizing or sinking process by unequal distribution of weight. Uneven loading is dangerous even if your boat is not overloaded. Remember in rough water excessive amounts of spray or water are easily shipped while underway, especially at high speeds. Water may also be taken in through hull damage or around fittings. No matter how it comes aboard it causes loss of freeboard and greatly reduces stability both highly conducive to sinking or capsizing. Keep in mind also the ever-present danger of falling overboard. Watch your footing and keep weight low and as near the center line of the boat as possible when working or moving about. Watch your step when boarding or departing. And be considerate of others in your boat. Play it safe. Don't overload or unbalance your load. Keep life jackets on all non-swimmers and keep everyone seated while underway. Operate your boat safely and enjoy the pleasure of boating. Don't become a boating accident statistic. [Music]