Nauticalia

As cannon power, and distances between battling ships increased, it became difficult for commanders to identify and co-ordinate their fleets. The Royal Navy generally operated in three squadrons - the Red, the White and the Blue - so decided to give each its own distinctive flag. The "Yellow Squadron" (and Ensign) never actually existed, but was the nickname for those who had been promoted Rear Admiral for serving time rather than merit (thus having a high rank but nothing to command). Such officers were referred to as "being left in charge of the beach", hence the choice of yellow! The three official flags remain today, but are used to identify a different set of divisions within the British Fleet as follows: WHITE ENSIGN - flown by naval vessels and members of the Cowes-based Royal Yacht Squadron. RED ENSIGN - can be flown by any British civilian/merchant vessel. YELLOW ENSIGN - for the captain with no ship!.(as explained earlier). BLUE ENSIGN - flown by vessels commanded by a person possessing an Admiralty Warrant