The Auxiliary Sail Endorsement is required for a Master who is in charge of a sailing vessel. The four-hour course covers Why Boats Fly, Commands, Parts of a Sailboat, Types of Sailing Vessels, and Rules of the Road for Sailing Vessels.

Prerequisites: An existing Masters license or concurrent enrollment in either the Master 100 Ton or OUPV to Master Upgrade courses are required for this endorsement, as are 180 days of sailing experience. Students are expected to have a basic understanding of sailing.