U.S. Marine Corps artillerymen assigned to 1st Battalion, 10th Marines, fire 155mm rounds using an M777 Howitzer weapons system during an artillery raid exercise. The exercise was in support of the Weapons and Tactics Instructor Course at Marine Corps Air Station Yuma, Ariz., April 4, 2015. WTI is a seven week training event hosted by Marine Aviation Weapons and Tactics Squadron One cadre. MAWTS-1 provides standardized tactical training and certification of unit instructor qualifications to support Marine Aviation Training and Readiness and assists in developing and employing aviation weapons and tactics.