Complex sentence: In addition to their primary role, marine troops are also used in a variety of other naval roles such as ships detachments, small scale raiding, boarding operations, naval vessel & port security, riverine missions, mess duty, and field day operations.
Split into simpler sentences: In addition to their primary role, marine troops are also used in a variety of other, naval roles. Stationed at naval bases or forming marine detachments onboard naval ships, they also conduct, small scale raiding, maritime boarding operations, security of naval vessels and bases, riverine missions, mess duty, and field day operations.