A landing scheduled by the tide

The date of the Inchon landing was not chosen by generals. It was the first day the tide would come high enough to float a landing craft over the mud.

Inchon has one of the largest tidal ranges in the world, around nine metres, and at low water the approaches are a mile of mud. That left a few hours on a few days a month, and those days are set by the Moon — this one fell just after new, when the Sun and Moon pull together and the tides run highest.