The National Mapping and Resource Information Authority (NAMRIA) on Wednesday clarified the role of official Philippine maps and nautical charts in depicting and protecting the country’s maritime jurisdiction in the West Philippine Sea.
In a statement, NAMRIA said the Philippines has formally adopted the name West Philippine Sea in government publications since 2012.
“NAMRIA places the label consistently across its official maps and charts, including administrative maps, topographic maps, thematic maps, and nautical charts used for navigation,” the statement read.
The central mapping agency explained that these materials serve practical and technical purposes in navigation, geographic information, and maritime safety.
They likewise function as reference documents for mariners, planners, researchers, and institutions both in the Philippines and abroad.
Amid ongoing public discussions, NAMRIA clarified how the country’s Exclusive Economic Zone (EEZ) is represented in official materials.
Under international law, the EEZ extends up to 200 nautical miles from the country’s archipelagic baselines.
NAMRIA noted that this creates a continuous curved boundary, similar to the edge of a circle, rather than a polygon formed by straight lines. Because of this configuration, the agency said a short list of coordinates would not accurately describe the maritime limit.
Instead, the EEZ boundary is represented using precise geospatial data derived from the archipelagic baselines defined under Republic Act 9522. This allows navigation systems and mapping software to determine maritime limits accurately.
NAMRIA added that its nautical charts follow international hydrographic standards and are used by both Philippine and foreign vessels navigating waters under Philippine jurisdiction.
These charts are also submitted to relevant international technical bodies, including the International Hydrographic Organization, ensuring that Philippine geographic information is integrated into the global maritime record and supports safe navigation and responsible maritime activity.
The agency reiterated that its mandate is to produce accurate and reliable geospatial information for the country.
By maintaining scientifically correct maps and internationally compliant nautical charts, the agency said it contributes to maritime safety, environmental management, disaster preparedness, and proper documentation of national territory.
