Section 68(5) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(5)The following indicator plates shall be established for use in boats by the Senior Naval Officers when the full ceremonial prescribed in Regulations 82 to 84 is not required:(a)A Red Disc with a white St. George's Cross painted thereon;(b)A Blue Disc with a white St. George's Cross painted thereon;(c)A White Disc with five black crosses painted thereon.All discs are to measure approximately 10 inches in diameter.
