How much of an iceberg sits under water?

Did you know that before the sinking of Titanic in 1912 there was no system in place to track icebergs to guard ships against collisions? Observing and monitoring icebergs was developed around the 20’s and 30’s. 

An iceberg has several shapes such as ‘dome’ (rounded top), ‘pinnacle’ (one or more spires), ‘wedge’ (a steep edge on one side and a slope on the opposite side), ‘dry-dock’ (eroded to form a slot or channel) and ‘blocky’ (steep, vertical sides and a flat top).

Icebergs range from 1 to 75 metres (3.3 to 246.1 ft) above sea level and 90% of it sits under water!