ICW Mile Marker shows your distance from the nearest Mile Marker on the Intracoastal Waterway (ICW). This information is necessary when transiting the ICW by watercraft. It is necessary to communicate with commercial watercraft on the more crowded sections of the ICW and commercial watercraft use mile markers, not Lat/Long. At best there are markers every 5 miles. In many places the are none. Using this app will allow you to communicate exactly where you are in the language the ICW Captains expect.