Getting the ice nice smooth

A group of us from school are going out ice skating on MOnday to I went down to check the place out today. No one was skating because it was a little warm but.. these guys were smoothing the ice..

What a weird contraption.. I have no idea how they would do this on an outdoor skating rink elsewhere but here, they use a huge drum filled with water with a tube at the end and a pipe with holes. The water just runs onto the ice.. Seems to work though.