(Warning, some NSFW language)

1984 - WHAT WAS HARDER, MARINE BOOT CAMP, MARINE OCS OR AOCS?
Having attended and passed all three entry-level programs, here are my thoughts about the differences:
As a Recruit at MCRD Parris Island, I was amazed at how well coordinated the training was.
Platoon - We had 72 recruits per platoon, all slept in a single, open squad bay, with 18 bunk racks on each side.
Series – Comprised of four platoons each, Lead and Follow Series. They started together and graduated together.
Company – Comprised of two Series, Lead and Follow.
Battalion – Comprised of two or four Companies depending on what year you attended.
Regiment – Comprised of four Battalions, 1st, 2nd and 3rd were male Battalions and 4th Battalion was the female Battalion.
While at Recruit Receiving (think of AOCS INDOC) we were assigned laundry numbers. Mine was #53, and when it was assigned, someone wrote it on my chest in large numbers with a black magic marker. This way we wouldn't forget our laundry number. At gear issue we walked along many tables under the screaming, buzzing control of DIs. I remember that you had to walk up to sock issue and scream your shoe size, but they were one size fits all, so it didn't matter. When you walked up to cigarette issue, you had to say whether you wanted Regular or Menthol. If you said you didn't smoke, you got a full carton of Menthol.
Every stitch of everything you owned was marked with your name and laundry number. We had a single Footlocker at the foot of the rack; it contained everything you owned, except your rifle, which was strapped on the frame of your rack [bunk bed], pointing downward if you were on the bottom rack, pointing upward when you were on the top rack. On black flag days we would do close order drill inside the squad bay. If we didn't do it correctly, we'd put our M16s away and use the footlockers instead; right shoulder arms with a footlocker doesn't work, and they would all crash on the deck, and then hell broke loose.
We had three Drill Instructors; they would rotate who had the duty to sleep in the SDI office, we would never be alone. Two DIs wore green cartridge belts with a large brass buckle with a Marine Corps emblem affixed to the center of it, and the Senior Drill Instructor wore a black leather belt with a think traditional belt buckle.
Taps and Reveille were strictly followed. Everything was orchestrated. The training was constant, PT was brutal, but the DIs would have “school circle” to provide heartfelt training when needed. I learned constantly, and was drilled on my knowledge constantly. We learned to shit and piss on command, as we did it together as a platoon. We wore Sateen (old olive drab cotton uniforms) trousers and white tee shirts, with un-starched covers. When we passed our first bunk inspection and knowledge course (usually at 4-6 weeks) as a platoon, we got to wear cammie trousers, but couldn't blouse them until we completed the rifle range. Once we completed the rifle range, our hair was growing out a little and we could blouse our trousers and wear starched covers. The most important thing to the DIs was rifle qualifications, they would all bet one another on their platoon's outcomes. If a recruit wanted to quit, it was a big deal. The DIs would usually try to talk him into staying because quitting is not an option in boot camp. They keep you till you earn the title, break you physically or mentally then send you home or at some point decide you are no longer desirable.
Later in my Marine enlisted career I attended Marine Officer Candidate School (OCS) Quantico, we had only one Drill Instructor, He was called a “Sergeant Instructor” and we were called “Candidates.” The Drill Instructors were assertive but they didn't yell. We had lots of classes and field exercises. We would stay up past Taps every night to do homework, or read, or polish our boots and brass. Everyone had to be in the rack as TAPS played, but then the SGT Instructor would leave and we would get up and square away our stuff. Officers and DIs would find us in the head doing our brass at 2300 or so, and they would just say, “Hurry Up And Get Some Sleep.” I was surprised. It was still physically challenging, but we had almost no punishment PT. If anyone wanted to quit, they wouldn't try to keep you.
Finally I made a choice to join the Navy and become an aviator. At AOCS, the Drill Instructors were once again referred to as “Sir” and were in your shit constantly, about everything! You guys already know what it was like, obviously. Funny, I will never forget my DIs from Boot Camp and AOCS. I can't remember my DIs from OCS, they just didn't have the same intensity, and aren't a significant part of my development. Another distinction has already been mentioned: In boot camp, they tried to prevent you from quitting. In OCS, they didn't try to make you quit, but they'd let you if you wanted to, without anyone trying to talk you back in. However, in AOCS they tried to make you quit. The most intense experience for me was AOCS, significantly more intense than the other two by far, MCRD Parris Island boot camp was 2nd place, and then Marine OCS is a distant 3rd place. * CDR John Owens – AOCS Class 19-84