OK, here goes. I have some photo's of the coffin as well, but since others have shared them, I won't post mine. The last time I dove CSSP, the coffin was still where it has been for the last several years, so no one has moved it recently.
If you start at the dock that has the floating platform attached to it and you are facing the lake, off to the left a bit there are a double set of platforms (they have surface markers attached) from those platforms if you head off the back side towards the deeper water and swim about 40', there will be a rock ridge just prior to the drop off. If you follow the rock ridge into the deeper water (i.e. left, towards the plane end of the lake), the coffin will be at the end of the ridge in about 40' of water.
Sorry, I don't have any compass headings, but the coffin is easy enough to find when you know where to look.
Randy