Musical girl touring new docking facility (6)
I believe the answer is:
marina
'docking facility' is the definition.
(marina is a kind of docking facility)
'musical girl touring new' is the wordplay.
'musical girl' becomes 'Maria' (character in The Sound of Music).
'touring' is an insertion indicator (touring can mean going round).
'new' becomes 'n' (abbreviation as in New Testament NT).
'maria' going around 'n' is 'MARINA'.
(Other definitions for marina that I've seen before include "Yachting centre" , "Dock for yachts and cruisers" , "boating facility" , "Yacht station" , "seaside area" .)