Both depth settings and maximum depth capabilities of submarines are things best kept secret, and would certainly be tightly held during wartime. The US learned this lesson courtesy of a congressman, who wanted to reassure some of his constituents that their sons/husbands weren\'t in too great danger because the Japanese were setting their depth charges too shallow. His stupidity was, perhaps, matched only by that of the reporter who included the comment in his story, and the editor who printed it.

The IJN was, of course, quite grateful, and promptly corrected the problem.

J.T. McDaniel