Vessels sailing under the St. Lucia Country Flag are required to have on board this flag as part of flag state requirements that derive from maritime regulations in the International Code of Signals and the International Safety Management (ISM) Code. These codes are published by the International Maritime Organization (IMO) as an ongoing effort to reinforce maritime safety procedures and communications to the international maritime community. Fleet management companies and ship owners are responsible to ensure that each vessel in their respective fleets have the appropriate flag signage onboard to be in compliance. This flag is used to identify the flag state a vessel is sailing under and to communicate with other vessels under the provisions of the International Code of Signals.
The St. Lucia Country Flag is represented by a light blue background. A set of triangles adorns the central third of the flag, the base offset from the flag bottom and the tip offset from the flag top. Three triangles occupy the same spot. A white triangle is receded, being visible behind a black triangle. A more squat gold triangle is to the forward. They reflect native cultural dominance. The flag is designated to hold a proportional ratio of 1:2, height to length, respectively. St. Lucia lies in the Caribbean sea and the blue background is meant to reflect this. It is also intended to represent fidelity and be reminiscent of the blue sky. The gold triangle is meant to represent the abundant sunshine this region enjoys. The white and black triangles are intended to represent the interaction and cooperation of the black and white races who coexist in St. Lucia. They are shaped as progressively higher isosceles triangles as a tribute to the twin Pitons, or volcanic mountains that define the contours of this country's exotic landscape.