Conversation so far:
which came first the navy or the marines
The Continental Navy was established on 13 October 1775, and the Continental Marines were established on 10 November 1775
which division of the armed forces has the most airplanes
The Army has 5,117 aircraft, but the Air Force still has more with 5,199 aircraft.
which division of the armed forces has the most boats
The Army has only 118 watercrafts. While the Navy certainly has more vessels than this, Navy vessels are considered ships by some so the Army has more boats.

Question: which division is harder to get into
Self-contained rewrite: which division of the armed forces is harder to get into