Determining Whether a Point is Land or Water on Google Maps

In order to verify if a specific point on a Google Map is located on land or in water, consider the following options:

Google Maps Reverse Geocoding

You can use Google Maps Reverse Geocoding to identify the landform or geographic feature associated with the point. In the results, check the "types" field. If the type is "natural_feature" and the name includes terms like "sea," "ocean," or "lake," it is likely that the point is in water. However, this method has limited accuracy, as it may not always reliably determine whether the feature is above or below sea level.

Pixel Color Detection via Google Static Maps

An alternative, more accurate approach involves sending a request to Google Static Maps with the point's coordinates and a zoom level of 1. The response is a 1x1 pixel image. By retrieving this image on your server, you can then analyze the pixel color. Dark blue pixels typically indicate water, while other colors represent land.

Considerations

Note that this method is not suitable for detecting small bodies of water, such as streams or ponds. It is also important to keep in mind that the Earth's surface is constantly changing, so the accuracy of these methods may be affected over time.