SEA LIONS FOR NAVY?

Wairarapa Times-Age, 13 October 1939, Page 6

SEA LIONS FOR NAVY?

STRANGE SUBMARINE CHASERS.

It has just been suggested that if need arose again the British Navy would prove to be remarkably well equipped with submarine detection apparatus, said the “Manchester Guardian” in August. But not, one may suppose with some confidence, with one type of “apparatus” that was actually suggested and tested during the last war. Sir J. J. Thomson tells of it in his “Recollections and Reflections.” It had been put forward that “if sea lions were able to hear sounds made under water they might be used to detect submarines and thus these might be hunted down by a pack of submarine hounds.” The committee responsible for examining suggestions was impressed and carried out experiments; some performing sea lions were hired and tried, first in swimming baths, then in Bala Lake and then in the Solent. “The method used was to make a sound under water with a buzzer, or by hitting a metal plate with a hammer, and to place food at the source of the sound.” This worked well up to a point, and the sea lions soon learned to associate noise .with food. In Bala Lake the sea lions would come from three miles away When the sound was produced. But there were drawbacks:

“They were very, temperamental; sometimes they would only come from a fraction of this distance. On hot days they were decidedly less efficient than on cold; their speed, too, was slower than might' have been expected. They took at least forty minutes to travel three miles, so that any but a very slow moving submarine would get away from them.” It was thought that porpoises would have done better. In the Solent the sea lions were a failure; "there were generally several ships about and they kept turning aside to go to the one making the greatest noise at the place where they happened to be swimming." Which must jiave been a bit of a disappointment to the sea lions, who were thinking of food, as well as to the experimenters, who were thinking of submarines.