Visual distress signals (VDSs) allow vessel operators to signal for help in the event of an emergency. VDSs are classified as day signals (visible in bright sunlight), night signals (visible at night), or both day and night signals. VDSs are either pyrotechnic (smoke and flames) or non-pyrotechnic (non-combustible).
- Vessels on federally controlled waters (such as South Carolina's coastal waters) must be equipped with USCG–approved VDSs. All vessels, regardless of length or type, are required to carry night signals when operating between sunset and sunrise. Most vessels must carry day signals also; exceptions to the requirement for day signals are:
- Recreational vessels that are less than 16 feet in length
- Non-motorized open sailboats that are less than 26 feet in length
- Manually propelled vessels
- VDSs must be USCG approved, in serviceable condition, and readily accessible.