OA units

OA units

OA stands for Orbital Assault. While all marines receive OA training, there are dedicated OA divisions. Of the 29,160 Marine Divisions 22,700 are designated OA Divisions. The rest are special warfare units, Ultra Marines (Guard and protection) and Union Fleet Shipboard Units, Thor Gunboat crews and Attack Craft Units. OA Units use Drop Ships, Heavy Destroyer Suits and have a wide range of heavy assault equipment and the OA assault is trained in a more intensive manner.