FOAMY WATER DANGEROUS.

Auckland Star, Volume LX, Issue 46, 23 February 1929, Page 11

FOAMY WATER DANGEROUS.

The foiun of surf, or of a cataract, contains myriads of air bubbles, and will not support the human body like ordinary water. Writing to "Nature (London), J. S. Owens uses this fact to explain the vccent loss of life in a lifeboat accident 011 the English coast.. lie says:— '"Many reasons have been advanced for the drowning of the crew of the Rye lifeboat, but there is one which I have not seen referred to, and which, I think, must be to a great extent responsible. The first time I realised the importance of this was when standing on the rocks overhanging the rapids below Niagara. I noticed that the water was mixed to a great depth with air bubbles, and this seemed to me to throw light upon the failure of swimmers to survive the passage of these rapids. The human body has a density approximately the same as water, and a swimmer finding himself in water containing large numbers of air bubbles is in the same position as if attempting to swim in a liquid of a much lower density than water. Suppose, for example, the water contains 10 per cent of its volume of aiibubbles, the effect upon a mail attempting to swim in this would be the same as if in ordinary water lie tried to carry more than a stone weight upon his back. When the sea is very rough with a wind blowing on shore, there is usually a «urf, or a number of waves breaking simultaneously as they approach the shore, and this churns up the water so that for some depth it contains a considerable amount of air in the form of bubbles. This is the cause of the white appearance of such a surf. I do not think that people fully realise the danger of attempting to swim in such aerated water; the effect is perfectly obvious when once it is pointed out, but I have not folind that this danger is realised at all, and a warning as to its existence may not be out of place."