M-12 contact mine

This was a moored, medium contact mine, which was basically an improved version of the M-08.

The minimum distance between mines was 100 ft (30 m).

The M-12 could reportedly be connected in tandem with an M-16 mine; the second mine was released after the first was detonated.

The mine was introduced into Russian service in 1912.

The M-12 was formerly reported in service in China and North Korea.

Upgrades over the decades led to fundamentally new mines with more complex designs and...