U.S. Marines from the 2nd Reconnaissance Battalion, Battalion Landing Team, 1st Battalion, 9th Marine Regiment, 24th Marine Expeditionary Unit participate in sustainment training in Djibouti on March 18, 2010. The training includes a Helo-casting mission out the back of a CH-53 Super Stallion helicopter and a closed-circuit dive. The 24th Marine Expeditionary Unit is a rapid-response force that performs various full-scale missions, from humanitarian relief efforts to combat operations.