sea level

This term serves as a global geodetic datum, providing a consistent baseline for calculating the elevation of landmasses. It is primarily used in geography, cartography, and aviation to ensure that altitude measurements are standardized across different regions.

Grammatically, the term is treated as an uncountable noun because it refers to a conceptual average or a specific reference plane rather than a discrete object. Consequently, it does not have a plural form and is typically used with the definite article "the" when referring to the global standard.