Wainwright has a small book on the Coast to Coast -- he, of course, is the one who defined it. Go4awalk.com has the GPS waypoints corresponding the the key waypoints Wainwright chose.
The easternmost waypoints were the ones I explored. 191 is the last point where you put your toe in the water next to the Bay hotel in Robin Hood's Bay. The first point is about 168 miles to the west on the Irish Sea at St. Bees. Point 187 is a High Hawsker which is where I got to reversing the points from the toe-dipping. With practice, this is doable. See all of the points here.