High-speed navigation brings its own problems. These are mainly concerned with time and space, and the inability to carry out many of the normal functions associated with navigation due to the motion of the boat. The time available for navigation is compressed and, at 30 knots, a buoy sighted 1 mile ahead is just two minutes away. Decisions have to be made quickly and the navigator needs to be presented with information in a readily usable form. Many of the traditional techniques of navigation can no longer be used easily, and new techniques which take into account the high-speed environment have to be developed.