the navy scouts and raiders were created before the navy combat demolition units (ncdus). the scouts and raiders were first formed 15 august 1942, nine months after the attack on pearl harbor, from the observer group, a joint marine corps–army–navy unit. the observer group was the first unit trained in amphibious reconnaissance. they trained in inflatable boat insertions from submarines around the chesapeake bay and at the amphibious training base (atb) little creek in virginia and in fort pierce, florida. they were training for an intense clandestine mission in north africa.