Scaling in Silhouette Marine Corps recruits climb an obstacle course during training at Marine Corps Recruit Depot San Diego, April 10, 2026. The O-Course is a series of obstacles designed to build recruits' strength, agility, endurance and confidence. SHARE: Download: Full Size (1.41 MB) Tags: physical fitness, recruitment, training, marine corps Credit: Marine Corps Lance Cpl. Adrian Guerrero Martinez VIRIN: 260410-M-XO045-9860.JPG Photo Gallery