As the UK prepares to accept women into infantry roles, the first female US marines have been enlisted in ground combat roles.
As we continue to look into boot camp life at Parris Island, Forces TV followed 20-year-old Katherine Gray during her final week of training.
Katherine got to participate in and comment on the 54-hour endurance exercise known as the Crucible.
Teamwork is vital to complete it, but Katherine found that after three months of spending every moment with her platoon, it wasn't always easy to get along.
But the good thing about marine boot camp is that it provides many ways to channel that frustration into productive training and exercise.
And then there's the final nine-mile hike in the dark - not something many recruits look forward to - but that results in the award of an Eagle, Globe and Anchor badge if completed - the symbol of being a marine.
After completing the final stage of training, the marines have one last thing to do: formally graduate and be reunited with their families.