Giant sperm whales are very deep divers and may stay submerged from 20 minutes to over an hour. When they surface, sperm whales typically blow 20-70 times before redescending. They produce a visible spout made by the condensation of the moisture combined with a mucous foam from the sinuses. Giant sperm whales typically swim at speeds no faster than 10 km per hour, but when disturbed they can attain speeds of 30 km per hour.

Giant sperm whales are highly gregarious and group themselves roughly by age and sex in group sizes of 100 or more individuals. Loose family groups of about 30 individuals, however, are more common. Groups are often made up of either bachelor bulls (sexually inactive males) or "nursery schools" of mature females and juveniles of both sexes. Older males are usually solitary except during the breeding season.

Sperm whales use clicking noises for echolocation, but they also make a variety of other sounds including "groans, whistles, chirps, pings, squeaks, yelps, and wheezes" (Ellis 1980). Their voices are quite loud and can be heard many kilometers away with underwater listening devices. Each whale also emits a stereotyped, repetitive sequence of 3-40 or more clicks when it meets another whale. This sequence is known as the whale's "coda."