Rotten ice is loose term for ice that is melting, disintegrating, or otherwise formed, having water, air or contaminants between ice grains, causing the ice to be honeycombed. It forms on open water, when snowpack and ice are mixed together and other conditions. It may be transparent, causing it to look like new black ice. Though it may appear strong, rotten ice is weak — even several feet thick may not hold a person's weight (although it may hold a dog sled's weight). On land, it is difficult or impossible to climb. It melts more quickly than solid ice. Candle ice is a form of rotten ice.