The Handbook of Texas Boating Laws and Responsibilities
The Official Boating Handbook of the Texas Parks and Wildlife - Web Version
Table of Contents
Scuba divers or snorkelers must display a diver-down flag to mark their diving area.
Vessels must remain at least 50 feet away from the flag. If they have to approach the diving area, vessel operators must have permission from the person who placed the flag or the vessel displaying the flag.
Outside of 50 feet, vessel operators must operate at headway speed out to a distance of 150 feet away from the flag.
A rectangular red flag, at least 15 inches by 15 inches, with a white diagonal stripe is required on state waters by Texas law.
A blue and white International Code Flag A (or Alfa flag) is required on vessels on federally controlled and international waters.