A detailed map of the East Coast shoreline can be found on Google Maps. Google provides a detailed road map and satellite images of the coast. Searching for the following coordinates on the search box on the upper left will take you directly to the East Coast: 38.479143, -75.052758.
Google Maps is highly accurate because it is regularly updated. Google states that its currently-used satellite images are from 2015. Using Street View, you can examine the East Coast on the ground level. The images shown in the Street View are generally older than the satellite images. Some parts of Delaware, for instance, had been photographed in July 2014.
Bing Maps also offers a similar service. The same coordinates apply. Both Google Maps and Bing Maps offer GPS services.