What is midshipman hitch?

The midshipman hitch is a type of knot that is commonly used for securing a line to a post or a ring. It is so named because it resembles the uniform button on the coat worn by a midshipman in the Navy. The knot is very secure and can be easily untied, making it ideal for temporary uses. To tie a midshipman hitch, the line is first looped around the post or ring, then a bight is formed in the standing part of the line, and the bight is passed over the loop and pulled tight. The knot can be easily untied by pulling the bight back over the loop.