The emergency wreck-marking buoy is designed to provide high visual and radio aid to navigation recognition. It should be placed as close to the wreck as possible, or in a pattern around the wreck, and within any other marks that may be subsequently deployed. The emergency wreck marking buoy should be maintained in position until:
- The wreck is well known and has been promulgated in nautical publications;
- The wreck has been fully surveyed and exact details such as position and least depth above the wreck are known;
- A permanent form of marking of the wreck has been carried out.
Emergency wreck marking buoy can be used to mark a newly discovered hazard not yet shown in nautical documents. It has blue and yellow vertical stripes in equal number, with a vertical/perpendicular yellow cross top-mark, and displays a blue and yellow alternating light.