Chart datum

{
  "id": "MLC-T-MET-004264",
  "term": "Chart datum",
  "field": "Meteorology and atmospheric science",
  "definition": "The reference plane of zero depth used on a nautical or hydrographic chart, to which all soundings and tidal heights are referred. This level is established so that the water depth will seldom, if ever, fall below it. The specific level used for chart datum is typically an approximation of the Lowest Astronomical Tide (LAT).",
  "url": "https://mlchart.com/terminology/meteorology/chart-datum/"
}