CATNAV
- clearing line: a straight line that marks the
boundary between a safe and a dangerous area or that passes clear of a navigational
danger. (adapted from IHO Dictionary, S-32, 5th Edition, 826)
- transit line: a line passing through one or
more fixed marks.
- leading line: a line passing through one or
more clearly defined objects, along the path of which a vessel can approach safely up to a
certain distance off. (Adapted from IHO Dictionary, S-32, 5th Edition, 2696)