Map "empty" contains no creatures of either positive or negative values. Our group wants to experiment with getting divers to cluster together in small groups, and a map with no other stimuli will be excellent for testing our clustering algorithms. It is also good for testing raw exploration algorithms: some of last year's divers performed abysmally on this map, essentially giving up without even exploring the whole board. Others seemed to do quite well, moving around in random patterns and returning to the boat only at the very end.