The Collaborative International Dictionary of English v.0.48:

Naval \Na"val\ (n[=a]"val), a. [L. navalis, fr. navis ship: cf.
   F. naval. See Nave of a church.]
   Having to do with shipping; of or pertaining to ships or a
   navy; consisting of ships; as, naval forces, successes,
   stores, etc.
   [1913 Webster]

   Naval brigade, a body of seamen or marines organized for
      military service on land.

   Naval officer.
   (a) An officer in the navy.
   (b) A high officer in some United States customhouses.

   Naval tactics, the science of managing or maneuvering
      vessels sailing in squadrons or fleets.
      [1913 Webster]

   Syn: Nautical; marine; maritime.

   Usage: Naval, Nautical. Naval is applied to vessels, or a
          navy, or the things which pertain to them or in which
          they participate; nautical, to seamen and the art of
          navigation. Hence we speak of a naval, as opposed to a
          military, engagement; naval equipments or stores, a
          naval triumph, a naval officer, etc., and of nautical
          pursuits or instruction, nautical calculations, a
          nautical almanac, etc.
          [1913 Webster]

WordNet (r) 3.0 (2006):

naval
    adj 1: connected with or belonging to or used in a navy; "naval
           history"; "naval commander"; "naval vessels"