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Moored mines

The moored mine is the backbone of modern mine systems. They are deployed where water is too deep for bottom mines. They can use several kinds of instruments to detect an enemy, usually a combination of acoustic, magnetic and pressure sensors, or more sophisticated optical shadows or electro potential sensors. These cost many times more than contact mines. Moored mines are effective against most kinds of ships. As they are cheaper than other anti-ship weapons they can be deployed in large numbers, making them useful area denial or "channelizing" weapons.Moored mines usually have lifetimes of more than 10 years, and some almost unlimited. These mines usually weigh 200 kg (440 lb), including 80 kg (180 lb) of explosives (RDX). In excess of 150 kg (330 lb) of explosives the mine becomes inefficient, as it becomes too large to handle and the extra explosives add little to the mine's effectiveness.