In the case where the coastline is specified by a xy file you have to prepare an ascii file with extension .xy (or .xyz) containing the geographical coordinates of the coastline. The file format is two (or three) space separated floats (real numbers) for the x- and y-coordinate on separate lines for each of the points (in case of three columns in the file x and y are derived from the first two columns). You must also select the map projection in which you have specified the geographical coordinates.
NOTE: (.xy) or (.xyz) input files must be provided in metric unit [m]
In the case where the coastline is specified by a dfs1 file you have to prepare a profile file (dfs1) containing the geographical coordinates of the coastline. The x- and y-coordinate will per default be derived from item 1 and item 2, respectively, from the first time step in the file.