As nouns the difference between navigation and leadline
is that navigation is navigation (theory and practice of charting a course for a ship, aircraft or spaceship) while leadline is a leash or strap for leading an animal or leadline can be a sounding line; an instrument used in navigation to measure water depth.
navigation
Noun
(en-noun)
(uncountable) The theory, practice and technology of charting a course for a ship, aircraft or a spaceship
(uncountable) Traffic or travel by vessel, especially commercial shipping
(countable) A canal
leadline
English
Etymology 1
(verb "to lead")
Noun
(
en noun)
A leash or strap for leading an animal.
Etymology 2
(after the metal); the attached plummet is usually made from lead.
Noun
(
en noun)
A sounding line; an instrument used in navigation to measure water depth.