Missing Asset

There is an X on the map in grid AA0 (in the ocean), where I assume there is supposed to be a custom build area there. There is nothing visible there. As you enter the area where the "x" is, the water disappears, then reappears when exiting. I tried to mark location best I could. just a heads up for ya.  

Thanks, with the new rocks, many objects were broken, maybe I forgot to remove the trigger, thanks