sailing vs departure

sailing and departure both are nouns.

Word	Noun	Adjective	Verb	Adverb
sailing	Yes	No	No	No
departure	Yes	No	No	No

As nouns, departure is a hypernym of sailing; that is, departure is a word with a broader meaning than sailing:

Other hypernyms of sailing include going, going away, leaving.

sailing (noun)	departure (noun)
riding in a sailboat	the act of departing
the work of a sailor	euphemistic expressions for death
the departure of a vessel from a port	a variation that deviates from the standard or norm
the activity of flying a glider