A seagoing Federation service that the young Tom Paris longed to join before his father steered him into Starfleet, as he recalls during Voyager's visit to the Monean ocean world.
The Federation Naval Patrol is a maritime organisation operating on the seas rather than in space, and one of the few glimpses Star Trek offers of sailing as a career in the twenty-fourth century.
It is mentioned in the Voyager episode Thirty Days. Tom Paris explains that he grew up fascinated by the ocean and by old stories of the sea, and had hoped to enlist in the Naval Patrol. His father, Admiral Owen Paris, would not hear of it and insisted that his son follow the family tradition into Starfleet.
That frustrated ambition explains Paris's passion for the Moneans' world of water, and his decision to defy Captain Janeway to protect it, for which he is reduced in rank and confined to the brig for thirty days.