OK I found it. The second digging spot is up near Woodruff. There was a Giant Crab there to kill first to get safe access to the digging spot. Once you land on the Island go to the row boat and then go up to toward the center of the Island. This should take you up to Woodruff and if you kept going it would go back down to the other row boat on the other side of the island. This should work from either landing spot. Don;t go to the other side. Stay near Woodruff. Go to the side he is on and search a little ways off the edge of the highest bluff. There are no immediate rocks or any trees right next to the spot. I hope this helps?