150428-N-GZ947-005 PACIFIC OCEAN - USS Freedom, USS Stockdale and USS John C. Stennis participate in a group sail exercise. U.S. Navy ships are underway conducting an Independent Deployer Certification Exercise off the coast of Southern California. The exercise provides a multi-ship environment to train and certify independent deployers in surface warfare, air defense, maritime-interception operations, command and control/information warfare, command, control, computers and combat systems intelligence and mine warfare.