sailing vs going away

sailing and going away both are nouns.

Word	Noun	Adjective	Verb	Adverb
sailing	Yes	No	No	No
going away	Yes	No	No	No

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

Other hypernyms of sailing include departure, going, leaving.

sailing (noun)	going away (noun)
riding in a sailboat	the act of departing
the work of a sailor
the departure of a vessel from a port
the activity of flying a glider