The Republic of China Navy (ROCN; ) is the maritime branch of the Republic of China Armed Forces. The ROC Navy's primary mission is to defend ROC territories and the sea lanes that surround Taiwan against a blockade, attack, or possible invasion by forces of the People's Republic of China. Operations include maritime patrols in the Taiwan Strait and surrounding waters, as well as counter-strike and counter-invasion operations during wartime. The Republic of China Marine Corps functions as a branch of the Navy.