Highest Astronomical Tide Line

To determine the estimated Highest Astronomical Tide elevation (in feet, NAVD88) and the tidal station used, simply click on a section of coastline of interest.

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Data Disclaimer

Usage of this data is limited to general and emergency planning purposes only. Users must assume responsibility in determining the usability of this data for their purposes. It is important to note that LiDAR data used to create these data represents bare earth conditions at the time it was captured (2006, 2010, 2011, and 2015-2017); thus, topography may have undergone changes since initial mapping occurred. Neither the Maine Geological Survey nor the Department of Agriculture, Conservation and Forestry, nor its employees or agents: (1) make any warranty, either expressed or implied for merchantability or fitness for a particular purpose, as to the accuracy or reliability of the information shown on the map; nor are they (2) liable for any damages, including consequential damages, from using the map or the inability to use the map.

Video Tutorial

Frequently Asked Questions

The frequently asked questions provide more information about how the data layer was created, what it should be used for, usage limitations and general information on tides in Maine.

Data Download

The beach mapping shoreline change layers can be downloaded as shapefiles for use in any GIS software to perform further spatial analysis.


    Recommended citations for the project, web application, and datasets:

    • Project
    • Web Application
    • Data

      More Help

      Contact the Maine Geological Survey with questions at: mgs@maine.gov