This iceberg shaped like a giant visor looked so sleek in the water. It has two distinct waterlines, which indicates that it has changed its form since calving, and the big crack at the back suggests that it might change again soon. When chunks of ice break off an iceberg, its centre of gravity changes and it turns in the water – sometimes as much as 180 degrees when a large part separates. Only one ninth of an iceberg is above water, so if a large section breaks off underwater, its shape and form can completely change in a matter of minutes. I saw one large iceberg (over 100 ft high) do a complete somersault in the Sermilik fjord, and it is a truly spectacular sight.