A person in distress in the water, who is either forced into the water from some larger craft, or for example from an airplane, even if they are equipped with a life preserver, may suffer injury or death from the cold within a short space of time.
Even if supported on some form of open raft, the cold will be such that the person is unlikely to survive for any length of time, except in warmer climates.
Rafts are available in which an inflatable platform is provided for supporting a person, or persons, in the water, and on which a form of cover or enclosure is provided. Such rafts are relatively expensive, and are also of considerable size even when packaged and stored. As such they are not suitable for carrying for example on a light plane, or a small fishing boat such as may be occupied by one or two persons.
In addition to the large size and expense involved in a typical survival raft, such craft did not always offer adequate insulation from the cold. Thus usually the enclosure or cover for such a raft would not be insulated, and the occupants would suffer from the effects of the cold after occupying it for any length of time.
A further factor in the design of a typical survival raft, is the problem of providing a sufficient degree of rigidity, to maintain its shape during use in the water.
All of these problems are compounded, when it is attempted to design a survival craft for a single person, and to provide such a craft which is small and light weight, such that it can form part of the equipment of, for example, an individual on a canoe trip, or a fisherman, or the pilot of a small plane.
A still further problem in relation to the use of rescue rafts results from the action of the wind. Since such craft are of light weight, and ride on the surface of the water, they are susceptible to the action of the wind to a greater degree than more conventional craft such as boats. As a result, the wind is liable to blow such a craft a considerable distance, and in many cases may easily turn the craft over.
This factor becomes particularly critical when it is desired to provide a small scale rescue craft for individual use.