(b) (6)

All commercial manta ray viewing operation permit holders shall display on the permitted vessel the capital letter “M”, so as to be clearly visible on both side of the vessel, near the top of the gunwales or on the superstructure. If the vessel has. a valid identification number issued by the department and displayed pursuant to chapter 13-241, the letter “M” shall be displayed as a suffix to the identification number. Unless otherwise required, the letter “M” shall be no less than six inches high by three inches wide in black or a contrasting solid color to the background.