Why naval doctors and chaplains carry officer status

Do naval specialists such as doctors and chaplains hold military rank or only a professional title?

Doctors usually hold officer rank and chaplains have a special officer-like status; their professional authority governs situations within their specialty.

Doctors normally carry officer rank, including distinctions such as surgeon commander, while chaplains have a more unusual status. Rank establishes pay and standing within their specialist branch. It also gives other personnel a clear way to recognize the specialist's authority inside a military organization. In a medical emergency, professional authority overrides ordinary grade distinctions and the crew should follow the clinician directing treatment.