This section defines the geographical area to which the Act applies. The Northern Ireland inshore region comprises the sea and seabed within the territorial sea (out to 12 nautical miles) adjacent to Northern Ireland, and the landward limit of the region is also defined. The Northern Ireland inshore region includes tidal rivers and all the sea loughs (including Lough Foyle and Carlingford Lough). This also includes areas that would be open to the tide, apart from the fact that they are generally isolated from it by an artificial barrier, such as a closed weir, but where seawater may flow or be caused to flow (e.g. the Lagan Weir).