'Excluding the Great Lakes, the United States has over 88,000 miles of coastline.'
Determining coastline measurements comes down to the scale that is used. In large scale nautical charts, what is referred to as general coastline data for the 50 U.S. states amounts to only 12,383 miles of coastline, but when smaller scale charts are used, the measurement reaches over 29,000 miles. However, the National Oceanic and Atmospheric Administration (NOAA) uses very precise charts in administering the Coastal Zone Management program, and those charts indicate that including islands, inlets, etc., the U.S. coastline amounts to 88,612 miles.