It shall be unlawful for any boat or vessel licensed by the department pursuant to Code Section 27-2-8 to fail to have fixed securely on each side of the bow or pilothouse thereof, and displayed conspicuously in order that it may be read from a reasonable distance, a tag furnished by the department. It shall also be unlawful for any boat or vessel so licensed to fail to have painted upon the boat or vessel, in a size and upon such part as may be prescribed by the department, such numbers and letters to identify the boat or vessel. The paint used for such purpose shall be different from and in clear contrast in color to the boat or vessel on which applied. The numbers and letters so painted on the boat or vessel shall not be covered at any time while the boat or vessel is trawling, fishing, or taking any seafood.