ON March 10, 2009, then-president Gloria Macapagal Arroyo signed Republic Act (RA) 9522 — which amended certain provisions of RA 3046, as amended by RA 5446 — to define the archipelagic baselines of the Philippines and for other purposes. RA 9522 aims to, among other things, delineate national borders and help specify the territories over which the country has jurisdiction. That included, in Section 2 thereof, the Kalayaan Island Group and Bajo de Masinloc (Scarborough Shoal) as 'Regime of Islands,' which were not specifically provided in the laws it amended. From these defined archipelagic baselines, we measure the breadth of our country's territorial sea, contiguous zone, exclusive economic zone (EEZ) and continental shelf.

On Friday, President Ferdinand Marcos Jr. signed into law RA 12064, or the Philippine Maritime Zones Act, and RA 12065, or the Philippine Archipelagic Sea Lanes Act.