Moored Mines
Contact Mines These are the oldest types of ocean mines, consisting of a sphere with several finger-like projections sticking out of it. It was typically anchored to the ocean floor by means of a chain or wire, and was detonated when a ship struck the mine and broke one of the projections. An electricity-conduction solution was released and allowed a circuit to be completed, setting off a powerful explosion of TNT or other explosive. These types of mines are still in use today, though usually not by the more advanced military powers. They are relatively cheap and easy to produce, and U.S. forces in the Gulf War swept some. This is the kind of mine that Gilligan found in that episode of "Gilligan’s Island" — though, as I recall, Gilligan’s metal watch and necklace became magnetically "stuck" to the side of the mine, so Hollywood was taking a few creative liberties with the device. (They don’t ever do that, do they?)


Exercise & Training (ET) Mine MK 6
The most universal type mine ever to be used was created in 1918. Live versions were used extensively during both WW I and WW II. The North sea saw the majority of them, and unfortunately Scottish fishermen still come home every so often with a live one hung in their nets! The traditional ball and spike mine has been depicted in movies all over the world as THE MINE that all fear the most. Many other countries have copied the basic design and created their own versions. The Iraqis even used their version of the Soviet M-08, similar but smaller than the US MK 6, during the Gulf war. US MK 6 mines contained TNT type explosive and were operated by contact switch horns. Today the Mk 6 is used extensively as a training mine because it immolates the shapes of mines used predominately by opposing forces.