There are many artificial aids on the market for swimmers and not swimmers which could satisfy just a part of the above mentioned requirements but none, to the best of our knowl- edge, to satisfy all of them.

Moreover, this Multi Purpose Swimmers Aid (MPSA) could be used in the emergency cases, when a good artificial aid is an imperative, for not swimmers and swimmers, too.

For us, humans, swimming is not quite natural. There are very few people able to swim for a longer period of time. The multitude get tired after quite a short time in swimming. The main reason is the body constitution of a human. It is easy to see that fact by watching a swimmer, when he/she is swimming"fast". Then the water around him/her is like boiling. To swim in good style means not only to swim gracefully or elegantly, but also to swim faster. But then the best result of good swimming is that of securing maximum return of speed for a minimum expenditure of energy.

"Boiling water"around the swimmer is not the best solution. But, of course, a human is not a dolphin! All humans can be put into three categories: - not swimmers, - bad swimmers and - good swimmers.

A not swimmer is a person who is afraid to enter the deep water, because he can not breed there. This is true, especially when there are just small waves.

According to the"Law of Archimed", it is approximately 1/50 part of the human body which can be above the water, when not swimming and that is quite unsafe for a not swimmer to breed.

With the aid of the MPSA the had of a human is above the water, so that even not swimmers feel safely and confidently, right from the beginning.

There are very few people to be put into the category of"good swimmers". Most people are really bad swimmers. Many of them become victims in certain unexpected situations. They can be saved by using the MPSA, which makes the swimming not only safer but more pleas- ant, also.

Because of that, it is to expect, that a bad swimmer will easier and faster become a good one with the MPSA.

While the usefulness of the MPSA is easy to explain, for the categories of not/bad swimmers, some theoretical analysis are necessary to prove that for the category of"good swimmers".

According to the"Law of Newton"a human can produce the propulsion force, in order to move himself in water by pushing a quantity of water in the opposite direction, just like a jet- plane pushes the air to move forwards. The said law defines the reactive force"F"as a product of the mass of water"m", pushed in one second with the velocity"v", by the formula F=mUv

A good swimmer is trying to push more water and fast, in order to swim faster. To do so, he is obliged to make many strokes with his arms and legs, quickly. But then, of course, he is loosing energy and becomes tired.

The more detailed theoretical analyze teach us that the best result of securing a reactive force"F'is that of securing more of"m"instead of"v"because the pure losses of energy are proportional to the"v2". And this is exactly what the MPSA is offering to a swimmer! The invention will now be described by way of example and with reference to the accompa- nying drawings in which: Fig. l - is a plan view illustrating the MPSA. As indicated in the drawing it consist of two identicaln plastic bottles (1), preferably dry air-pressured, interconnected by a joint/handle (2).

Two of this MPSA will normally be used by a person, one for each hand, which means that he/ she will have 4"carynig volumes"to rely on. To increase the volume, lower portions of the same type of bottles (3) can be added by simply pressing them on the MPSA; Fig. 2 - illustrates the most convenient position of a not- or bad swimmer and of a tired swimmer, with the MPSA; Fig. 3 - practicing legs; Fig. 4 - possible positions of the MPSA, when the swimmer is facing the sky; Fig. 5 - swimming Crawl; Fig. 6 - the Back Crawl; Fig. 7 - the Dolphin-Butterfly Stroke; Fig. 8 - playing games with the MPSA.