Unless otherwise stated, the reference datum for determining the heights of land features on charts is typically what?

The reference datum for determining the heights of land features on charts is typically mean sea level. This means that the elevations and heights of features such as mountains and buildings are usually based on an average level of the sea, which provides a consistent point of reference regardless of tidal variations.

Mean sea level serves as a standard for maritime navigation charts and topographic maps, allowing mariners and other users to accurately assess elevations and land features relative to a generally accepted baseline. This datum is essential for ensuring that navigational information is reliable and consistent across various regions and chart types. By using mean sea level, charts can be uniformly interpreted by users navigating different waters and territories.

Other choices refer to specific water levels that can fluctuate with tides, such as mean high water and mean low water, which are less useful for providing a consistent reference for land elevations. Chart datum represents the lowest water level that can be expected to occur in certain tidal conditions and varies by location, making it unsuitable as a general reference for all land feature heights.