This Final Rule amends the Coast Guard’s merchant mariner manning regulations to align them with statutory changes made by the Howard Coble Coast Guard and Maritime Transportation Act of 2014. The Act allows oilers serving on certain offshore support vessels, towing vessels, and barges to be divided into at least two watches. This change increases the sea service credit affected mariners are permitted to earn for each 12-hour period of work from one day to one and a half days.