The exact division of territorial waters between Northern Ireland and Southern Ireland ('Southern Ireland' being coterminous with the territory of the modern-day Irish state) was a matter of some controversy from the outset. The Government of Ireland Act 1920 did not explicitly address the position of territorial waters although Section 11(4) provided that neither Southern Ireland nor Northern Ireland would have any competence to make laws in respect of "Lighthouses, buoys, or beacons (except so far as they can consistently with any general Act of the Parliament of the United Kingdom be constructed or maintained by a local harbour authority)".