Atmosphere over and near the sea
NOTE A marine atmosphere will extend a certain distance inland, depending on topography and prevailing wind direction. It is heavily polluted with sea-salt aerosols (mainly chlorides).
[ISO 12944-2:1998, definition 3.7.4]
Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global Standards