Main menu:
How the Chart is made
Click on images for full-size preview (Click image again to return to website)
Select the shoreline and right click. Then Select 'Copy' – this places the shoreline onto the clipboard
Select the draw polyline tool
Now draw a polyline that connects one end of the shoreline section to the other end of the shoreline section, and encloses a reasonable area of land
Now hold down 'ctrl' and select the shoreline and polyline together – then right click and choose “merge polylines”
Once they are merged right click on the object and select “convert to polygon” – select the type of polygon you want to make
Now hit 'ctrl-v' and your original shoreline will be pasted back into the chart