Fix

A fix is the vessel’s position established at a point in time from intersecting position lines: cross bearings, a bearing and a range, two ranges, a running fix advancing one bearing along the track, or a GNSS fix. A good visual fix uses three position lines that cross in a tight cocked hat; a large triangle warns of an error. Best practice fixes the position at regular intervals against soundings and the depth contour as an independent check on the electronic position.