Okay, I can't find the one that was posted here (the purple storm-at-sea one). But I did find out that it is based on a Marcia Hohn pattern. On her Storm At Sea pattern, her testers have made a couple of storm-at-sea quilts with an image in them. One's a heart and the other's a cross.
http://www.quilterscache.com/S/Storm...ock_Page3.html
This shows the diagram for the heart one. If you click on "Eugene" in the "made by" list, you'll see the cross.