What kind of ship would take up patrol duty, seeking enemy ships across the world's oceans?

The type of ship that would take up patrol duty, seeking enemy ships across the world's oceans is a frigate. Frigates are specifically designed for anti-submarine warfare and escort missions, but they also have capabilities for reconnaissance and patrol. Their relatively smaller size allows them to operate efficiently in a variety of environments, and they are equipped with advanced radar and sensor systems to detect and track enemy vessels.

Additionally, frigates provide a balance between offensive firepower and defensive capabilities, making them well-suited for patrolling operations where they need to engage potential threats while also gathering intelligence on enemy movements. Destroyers and submarines may also have patrol capabilities, but destroyers are larger and primarily focus on air defense and surface combat, while submarines operate stealthily underwater and are less suited for wide-area surface patrol operations. Carriers serve primarily as mobile airbases and are not designated for patrol duties in the same manner as frigates.