Others have given great advice. Their is an alternative. You could join the Merchant Marine Academy. From what I read, once you graduate you have options that allow you to go either civilians or military. You will have to do reserve duty if you dont go active.
Per their website
No other federal service academy offers you the career options of Kings Point. You may choose to seek your opportunity as a ship's officer at sea, ashore in the maritime and intermodal transportation field, or as an active duty officer in one of the Armed Forces. Since the Federal Government has provided your education at Kings Point, you will have a service obligation when you graduate -- in the maritime and/or transportation industry, and to Armed Forces Reserve duty.
Per wikipedia
Midshipmen at Kings Point have a wide variety of options upon graduation. Unlike the nation's other Federal Service Academies, graduates of USMMA are required to fulfill their service obligation on their own by providing annual proof of employment in a wide variety of occupations as approved by
MARAD for a specified period of time.
Graduates may elect to fulfill their service obligation by working as licensed officers on US-flagged merchant vessels, as civilians in the
maritime industry, or as active duty officers in any branch of the
uniformed services of the United States, including the Army, Navy, Marine Corps, Air Force, Coast Guard,
Public Health Service, or the
National Oceanic Atmospheric Administration. Regardless, graduates are required to maintain their US Coast Guard-issued merchant marine officer's license for a period of at least 6 years.
Those graduates electing to enter the civilian work force in the maritime industry, and those sailing in the
Merchant Marine, are also required to maintain their
Navy Reserve commission (or another reserve component commission in the Army National Guard or Reserve, Marine Corps Reserve, Air Force National Guard or Reserve, or Coast Guard Reserve) for a period of at least 8 years after their commissioning as officers, and are required to serve in the maritime industry for at least 5 years following graduation.