The function of a coast guard varies, depending on the nation where it is located. Almost every nation which has a shoreline has this type of organization, but its nature can vary from a branch of the military to an all-volunteer civilian agency. Members of the coast guard, known as “Coasties” in some regions, can perform an assortment of tasks related to navigation, national security, and ocean safety. They are usually posted in harbors, and may maintain fleets of trucks, helicopters, fixed-wing aircraft, and other support vehicles in addition to boats.
Origins of the modern coast guard can be found in the 1800s, when several communities established civilian groups to aid ships in distress. These groups would send out rescue and salvage operations as needed, and many of them supported organized government efforts to create navigational markers like buoys and lighthouses. The improvements in maritime safety created by such groups spurred the organization of more formal coast guards.
When a coast guard is organized by the government, it is usually a cross between the military and a law enforcement agency. Members are responsible for protecting the shoreline, enforcing immigration and drug laws, and monitoring vessels for safety issues. Members are also expected to assist vessels upon request. Maintaining navigational markers and warnings is also generally the responsibility of this organization.
Civilian organizations tend to focus on things like search and rescue, maritime research, assistance to distressed vessels, and public safety outreach. Military coast guards also perform these tasks. Civilians generally cannot get involved in law enforcement, although they may report issues which appear to pertain to national security to government officials. A civilian group may be a privately funded agency with paid employees, or an all-volunteer force. Rural and isolated regions may rely on volunteers because the population cannot support a full-time coast guard.
In the case of coast guards associated with the military, members are treated as active duty members of the military, which entitles them to the same pay and benefits that members of other military branches receive. Guards are generally kept posted in their home nations for security, but they can potentially be deployed to other locations, and they may be loaned to law enforcement agencies and allied nations to assist with projects like arresting drug smugglers or improving border safety programs.