DriverDivots, on 22 Feb 2016 - 2:28 PM, said:
Just curious, where did you pull the 1m data from?
https://coast.noaa.g.../geoid12a/data/
It's a complicated process using a paid version of Globalmapper to export the data. Took me many hours to extract so I'm not going to attempt to explain the steps. The site is full of great data for the US but you'll need a 3rd party GIS programme.