The Maritime Zones, 1999, No. 18 25 August 1999(1) which repealed the The Territorial Sea Act, 1971, and the Exclusive Economic Zone Act, 1977 states that the contiguous zone of Samoa comprises that part of the sea within 24 nautical miles from the baseline from which the breadth of the territorial sea is measured. The Government of Samoa may exercise any powers and take any measures in relation to the contiguous zone as may be necessary in order to prevent or punish infringements of its laws that relate to customs, fiscal matters, immigration, environmental protection or health, or any other law as prescribed under this Act.
https://www.un.org/depts/los/LEGISLATIONANDTREATIES/PDFFILES/WSM_1999_MaritimeZ.pdf
The list of coordinates can be found under the Samoa Maritime Zones Order 2017.
https://www.un.org/depts/los/LEGISLATIONANDTREATIES/PDFFILES/WSM_2017_MaritimeZ.pdf