Coastal states need a maritime arm for safety and law enforcement. A coast guard is a national service responsible for search and rescue, maritime safety, pollution response, and often customs, immigration, and security duties in coastal and territorial waters.

Coast guard vessels and aircraft patrol, board ships, assist craft in distress, and maintain aids to navigation. In some countries the coast guard is a military service; in others it is civilian. Authority and equipment vary widely, but the core missions of rescue and safety are nearly universal.

Merchant ships and fishing vessels rely on coast guard coordination during emergencies. Cooperation between neighboring coast guards improves coverage in busy or remote waters. The distinctive color schemes and markings of coast guard units make them readily identifiable at sea.

• National maritime safety and enforcement service
• Handles rescue, safety, pollution, and security tasks
• Operates ships, boats, and aircraft
• Partners with commercial shipping in emergencies