I really struggled with this event at OCS! If I wasn't so tall, it would have been worse. If you struggle with the Obstacle Course, I strongly recommend you go to all the remedial sessions like I did. These took place during stretch PT. I made sure to stretch and foam roll after lights. Remedial O-Course practice was fun. You go with maybe 20 candidates and there are a few PTIs. They were really helpful, and this was one of the only times I got to chit-chat with other candidates from other platoons.
At OCS, when I went, the obstacle course was graded, but not a graduation requirement. This meant that if you got a 70 on it, you could still pass OCS as long as your other physical fitness grades are high enough.
The obstacle course bars are THICK. Much thicker than a pull-up bar. If you ever see construction scaffolding, the bars are around that thickness.
At OCS, you must do the techniques the instructors tell you to. At TBS, some company commanders let you use "any method." This video is done by a PTI at OCS, so if you see any fancy stuff in any other videos, shelve it for now.
Marine Corps Obstacle Course official PTI video
One of the first thing the instructor says in the video is kicking your feet outwards. At OCS, try to learn both kicking to the right and to the left. Right handed people naturally kick to the left, and left-handed people kick towards the right. I was lucky to be in a fireteam with a left-handed candidate and a right-handed candidate who was a leftie gymnast. So when we did the obstacle course for a grade, we made sure to line up together and go at the same time, so that we got the lane we felt most comfortable with. My rack mate paired with the left-handed candidate, while I paired with the gymnast, who was my best friend and "twin" at OCS. She was also the only female to do the college-boy roll, and had the best o-course time in our platoon.
If I remember correctly, here are the requirements:
Males:
1 minute is perfect, 2 minutes is minimum passing.
Females:
2 minutes is perfect, 4 minutes is passing.
The techniques I personally used:
Knee-high logs-right hand, right foot, swing left leg over.
High-bar- Chicken wing with right arm, kick to the left
Combo- Jump to bar, then hook feet on TWO bars, swing up to a sitting position, slide. I usually hooked my left foot a bit before my right, because it took less ab work than hooking both at the same time. You can do that. I walked down two logs.
Wall- kick over to the left
High log- Jump high and forward, aiming to get hips on the log. Swing to the left. In the video, this is the third method
Logs- A lot of people do a hop over them. I did this spinning motion, which is allowed, and it saved a lot of energy. At the 1:00 mark in this video, the man is doing the third method in the other video, but adding the spinning motion. I place two hands on the log, and swing my left leg up so that I'm lying sideways on the log. I then swing my right leg up and keep spinning in that direction, taking a blind landing. Each log I do a complete spin around. In the video, this is the third method but I do the spin to get momentum to do the subsequent logs.
Double Bars- there is this "ditty" the instructors make you memorize and both of the methods I was okay with. It has to do with in-board and out-board legs. I did the second method, which is basically the first method but your outboard leg helps you get your in-board leg up.
Rope- I used the J-hook. I was terrible at the rope and fell from the top once. I think this is where I broke my foot. A lot of people feel more secure with the S-method, but I think it wastes energy and is time-consuming. However, since the rope is the most dangerous obstacle, do whatever makes you comfortable. At remedials, practice going half-way up a bunch of times before attempting to go all the way up. The initial hook onto the rope is what people struggle with, the rest is endurance. You can practice the hooks in the back staircase in your squadbay. There is a rope hanging from the pull-up bar.
DO NOT USE BATES LITES ON THE OBSTACLE COURSE. They are terrible for the rope.
Good luck and be safe!