A letter was dispatched from the Chief of Naval Operations in November 1941 inquiring if it might not be desirable to place torpedo nets within the harbor itself. (Torpedo nets had been laid at the channel entrance.)

The admiral in command at Hawaii brushed aside these well founded fears. He obviously thought of torpedoes as being launched from SHIPS or SUBMARINES and could not bring himself to accept the idea of Japanese bombers & fighters actually attacking his ships or their base from aircraft carriers

A Succeeding admiral also rejected the idea of torpedo nets within the harbor. His decision rested on the technical opinions of ordnance experts that torpedoes could not be used effectively in Pearl Harbor.

They did not know about the new shallow water torpedo, designed by the Japanese, which could and would be launched in Pearl Harbor.

As it turned out the majority of the damage caused by the Japanese attack came from torpedoes especially modified for use in shallow water.