Join Big Animals Expedition leaders, snorkeling, swimming, free diving and photographing sperm whales! In past experiences, they have observed Dominica’s West Coast hosting approximately five sperm whale families, each with five to nine cetaceans. Females and their calves comprise the majority of these groups, although we occasionally encounter males, who are 45 to 55 feet long; thirty percent larger than the females. Families frequently socialize by playing in the water.