The Sperm whale is a summer visitor to Icelandic waters, the whales seen are probably all adult males who often swim in small tight groups, the females remain further south with their calfs. This leviathan can reach the size of up to 20 m. and weigh over 50 metric tons. A highly specialised diver and hunter of giant squid, this huge animal shows some very special adaptations to its extreme lifestyle. Among these is the giant head-case which is filled with oil, very sough after in earlyer times it has long been replaced by other products. Sperm whales were hunted off the Icelandic coast until around 1980, they have since been fully protected.