Providing forces for maritime search and rescue, icebreaking, and servicing of maritime aids to navigation is a specific wartime function of which military service?

Providing forces for maritime search and rescue, icebreaking, and servicing of maritime aids to navigation is a specific wartime function of the united States Coast Guard. This kind of functions are performed by most countries coast guards during the time of war. Along with the mentioned functions, it also closely monitors the water boundaries of the country.