Regular Membership in the Naval Order
Any United States citizen who has served, or is serving, as a Commissioned Officer, Warrant Officer or Enlisted person of the Navy, Marine Corps, Coast Guard and any other Federal military maritime service of the United States, including the commissioned corps of the U.S. Public Health Service (USPHS) and the National Oceanic and Atmospheric Administration (NOAA) or citizens who are an eligible officer’s, Warrant Officer’s or Enlisted person’s descendant over eighteen years of age, shall be eligible for Regular membership; provided, however, that all who have left the service shall have departed with an honorable record or shall have been honorably discharged, and, in the case of currently-serving enlisted personnel, the last enlistment shall have been completed honorably.
(Naval Order Associate and Honorary Membership descriptions can be found HERE.)
A Spotlight on NOAA and the US Public Health Service
The NOAA Commissioned Officer Corps is the smallest of the seven uniformed services in the United States, with over 300 members. A description of their areas of expertise can be found at NOAA and involves operating ships, aircraft, research projects and many other activities.
(Photo above: The officers and crew of NOAA Ship Reuben Lasker, a fishery research vessel. Source: https://www.omao.noaa.gov/find/media/images/officers-and-crew-noaa-ship-reuben-lasker-prior-ships-may-2-commissioning-ceremony )
The work of the 6000-strong public health professionals at the US Public Health Service Commissioned Corps is described at PHSCC. Included in their work is public health promotion, disease prevention and disaster response, such as the October 2017 deployment to Puerto Rico in the wake of Hurricane Maria. (Photo of USNS Comfort in San Juan, Puerto Rico on 3 October 2017, above from http://www.navy.mil/submit/display.asp?story_id=102710)