Vessels sailing under Sint Maarten 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 Sint Maarten Country Flag is represented by two equally proportioned horizontal stripes. The top stripe is red and the bottom is blue. A white isosceles triangle backs up to the mast, or left side of the flag and points toward the fly, or right side. This triangle contains a depiction of the Sint Maarten Coat Of Arms. This contains a rendering of the Philipsburg court house set in a blue shiel and orange border. There also is pictured a monument that marks the boundary line between the French and Dutch portions of the island. Saint Martin, a French territory encompasses half the island while Sint Maarten, the Dutch portion which is an autonomous territory of the Kingdom of the Netherlands lies on the other half. The shield also holds depictions of yellow sage flowers and green sage leaves. A yellow ribbon is tied about the bottom of the crest, reading Semper Progrediens, or Always Progressing. Above the shield, a yellow half sun is shown with a gray pelican flying across it toward the right of the viewer.