I really like it! It appeals to me more than other Anna-smoosh names like [name_f]Annabeth[/name_f] (only barely for this one, but the others by quite a large margin), Annevieve, and [name_f]Annegret[/name_f]! I’m such a huge fan of [name_f]Annie[/name_f] and [name_f]Vera[/name_f] that I’d probably use one of the two of those, but I do love the idea of using a nn that contains parts of both if you’re going after a compound name like Annavere! I agree that I would spell it [name_f]Navi[/name_f] over Navie; I also would’ve said [name_f]Navie[/name_f] like [name_f]Navy[/name_f].
speaking of compound names…
A family friend has a granddaughter named Ann@dore (like [name_f]Anna[/name_f] + [name_m]Theodore[/name_m]) which now that I realize it, also seems very you! I would love to see it used more. I think she goes by the full name but there are a lot of fun nns with her too!
Good luck!