Navy Lt. Chris A. Cruz, a 29-year-old medical doctor for Combat Logistics Battalion 31, 31st Marine Expeditionary Unit, and a native of Arlington, Texas, provides an intra-articular, sub-patella injection for pain relief during Exercise Koolendong 13 here, Sept. 4. The doctors and corpsmen of the 31st MEU’s logistics combat element and command element operate multiple aid stations to maintain the health of more than 250 Marines and Sailors training in the area. Koolendong demonstrates the operational reach of the 31st MEU and reinforces why it is the force of choice for the Asia-Pacific region. Also participating in the exercise is the Marine Rotational Force – Darwin and soldiers of the 5th Royal Australian Army. The 31st MEU brings what it needs to sustain itself to accomplish the mission or to pave the way for follow-on forces.