U.S. Marines assigned to the 13th Marine Expeditionary Unit drop from a CH-46 Sea Knight helicopter assigned to Marine Medium Squadron 163 to the flight deck of the amphibious assault ship USS Boxer (LHD 4) while conducting a fast-rope exercise in the Indian Ocean on March 24, 2011. The Boxer is the flagship of the Boxer Amphibious Ready Group, which is underway with the 13th Marine Expeditionary Unit on a western Pacific Ocean deployment.