Water Framework Directive (WFD) Coastal Waterbody unit within Irish waters. According to the WFD Article 2(7) “‘Coastal water’ means surface water on the landward side of a line, every point of which is at a distance of one nautical mile on the seaward side from the nearest point of the baseline from which the breadth of territorial waters is measured, extending where appropriate up to the outer limit of transitional waters.”