Indexes of World War II History books will seldom make reference to NETS or NET TENDERS. One exception is the book Titled AT DAWN WE SLEPT, The Untold Story of PEARL HARBOR" by Gordon W. Prange.

The following information is taken from this book:

At the time of the Pearl Harbor attack on Dec. 7, 1941 the Net at the PearL Harbor channel entrance was not a Submarine Net, that extended down to the bottom of the channel with anchors. It was a torpedo net which only extended in depth as far as the keel line of the deepest draft vessels to be protected. It was free to swing forward and upward when struck by a torpedo. This net prevented the enemy from sending a torpedo up the channel like a bowling ball barreling down an alley.

At least one midget submarine did get through the Pearl Harbor channel net. It could have happened when the Net Gate Vessel opened the protective net for the minesweepers Condor and Crossbill at 4:58 am and left gates open until 8:46 am. In a pinch the sub could also have edged in under the net, which extended to a depth of 45 feet whereas the deepest part of the channel was 72 feet. The midget submarines measured 20 feet from keel to conninq tower, so this gave some 7 feet of leeway under the net.

No other nets were in place in the harbor or around any of the large ships. The navy brass at Pearl Harbor did not believe that aerial torpedoes could be used within the confines of the harbor because of the torpedo run distance required to set off the exploding device.

Unknown to the Americans the Japanese had developed a torpedo that could be launched from planes within the confines of the harbor.

The possibility of torpedo nets around the ships in Pearl Harbor worried the Japanese. If the Americans had placed the nets, the torpedo attack would be almost useless in spite of the skill developed in the revolutionary breakthrough in the torpedo design.

In the event the Japanese discovered that nets protected the American ships, it was decided to make aerial bombings only against them, giving up aerial torpedo attacks.

Through their espionage agent in Hawaii the Japanese did learn that there were no torpedo nets around any ships at Pearl Harbor.