The Tuvalu Contiguous Zone was measured from the following; i) the low water line of the seaward side of the normal baseline (coast), the low-water line of the seaward side of the reef fringing the coast and bounding any lagoon waters adjacent to any part of that coast. (ii) The archipelagic baseline measured seaward with a distance of 200 nautical mile (370.4 km; 230.2 mi) from the nearest point of that archipelagic baseline. MarZone delimitation software was used to generate territorial sea limit using the World Geodetic System 1984 (WGS 84) reference datum as stipulated under the Tuvalu Maritime Zones Act 2012.
In the Contiguous Zone a State can exert limited control for the purpose of preventing or punishing "infringement of its customs, fiscal, immigration or sanitary laws and regulations within its territory or territorial sea". This will typically be 12 nautical miles (22 km; 14 mi) wide, but could be more (if a state has chosen to claim a territorial sea of less than 12 nautical miles), or less, if it would otherwise overlap another state's contiguous zone.
