Senator Francis "Tol" Tolentino has filed a bill that seeks to "institutionalize" the West Philippine Sea (WPS) by formalizing the designation of the said nomenclature as part of the existing laws of the land.

"The measure would further reinforce the Philippines’ claim to the disputed territories found on the western side of the archipelago," he said.

Under Tolentino’s Senate Bill (SB) 405, the maritime area—including the air space, seabed, and subsoil—on the western side of the Philippine archipelago is hereby named as the “West Philippine Sea” or “Kanlurang Dagat ng Pilipinas” as part of the Philippines’ “inherent right to designate the names of its maritime areas,” and consistent with the 2016 Award of the Arbitral Tribunal of the Permanent Court of Arbitration (PCA).

In 2016, The Hague Tribunal invalidated Beijing’s “nine-dash line” doctrine over the entire South China Sea (SCS) region following an arbitration case filed by the Philippine government on Jan. 22, 2013.

China’s nine-dash line unilaterality encroached territories of other Southeast Asian countries, including the WPS.

According to Tolentino, the bill is in response to the archipelagic doctrine embodied under the United Nations Convention on the Law of the Sea (UNCLOS), in which the Philippines is granted a territorial sea of up to 12 nautical miles, a contiguous zone of up to 24 nautical miles, and an exclusive economic zone (EEZ) of up to 200 nautical miles where the WPS is located.

“As patriotic citizens, we should assert our sovereign rights over our EEZ for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superjacent to the seabed and of the seabed and subsoil of our EEZ with the concomitant duty to protect and preserve the marine environment therein,” Tolentino’s explanatory note stated.

The Department of Foreign Affairs (DFA) earlier during the 55th ASEAN Foreign Ministers’ Meeting in Cambodia has asserted its territorial ownership of the disputed territories by citing the arbitral award, noting that The Hague ruling as well as the 1982 UNCLOS “are the twin anchors of policy and actions” of the Philippines on the WPS.

Under SB 405, territories under the WPS include the Luzon Sea and the waters around, within, and adjacent to the Kalayaan Island Group in Palawan, and Bajo de Masinloc or also known as Scarborough Shoal in Zambales, among others.

Section 2 of the bill mandates the National Mapping and Resource Information Authority (NAMRIA) to produce and to publish charts and maps of the Philippines reflecting the nomenclature WPS or the Kanlurang Dagat ng Pilipinas.

Furthermore, the bill, once approved into law, mandates the national government through the DFA to deposit a copy of the future Act and other relevant documents with the Secretary General of the UN and notify accordingly all relevant International and intergovernmental organizations, such as the United Nations Statistical Commission, the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization (UNESCO), the United Nations Group of Experts on Geographical Names (UNGEGN), and the International Hydrographic Organization (IHO).

Tolentino’s measure also directs all departments, subdivisions, agencies, and instrumentalities of the Philippine government to use and employ the name WPS or Kanlurang Dagat ng Pilipinas in all communications, messages, and public documents, and “to popularize the use of such name with the general public, both domestically and internationally".

The bill is also specific that all private institutions, organizations, and establishments, whether organized under Philippine law or foreign law, operating within the Philippines, or transiting in Philippine territory are hereby directed to use the name WPS or Kanlurang Dagat ng Pilipinas in all communications, announcements, and messages, both domestically and internationally.