The Seven Seas

I’ve been assuming that whales sail the Seven Seas. But since most assumptions are flimsy at best, I decided to look into it.

Which Whales?

“The ocean covers 71 percent of the Earth’s surface and contains 97 percent of the planet’s water . . .”
— National Oceanic and Atmospheric Administration*

Of course, I know the many types of whales differ in their feeding, breeding, and migration patterns. So I checked only on the four that are most well-known by whale watchers: the Blue, Grey, Humpback, and Sperm whales. Notice I left out the Orcas, which, although known as ‘killer whales’ are actually dolphins.

Which Seas?

Like most of us, I grew up hearing about sailing the Seven Seas. It got underlined for me during a time we lived aboard our sailboat and were members of the Seven Seas Cruising Association.  Even though we dreamed of many sea voyages, I never bothered to find out what the seven were.

Local Knowledge

The Seven Seas phrase was used by cultures as early as the Sumerian (2300 BC) where the number seven was connected to many ideal forms. From then on, local geography guided what people included. With the early Greeks, the Seven Seas phrase entered Western literature and included the Aegean, Adriatic, Mediterranean, Black, Red, Caspian seas and Persian Gulf.


Changes in human culture changed the seas. In the medieval era with its Christian influences, the Dead Sea and the Sea of Galilee were added to be part of the Red Sea. With the new navigational tools of the Renaissance, global exploration expanded maps of both land and sea. Once the Americas were discovered the waters of the globe were re-organized close to our current view.


The Seven Seas kept changing as geographers decided how big and how separate a body of water had to be to qualify. The seven largest are: Pacific, Atlantic, Indian, Arctic, Mediterranean, Caribbean, and the Gulf of Mexico. Current geography has left out the last three, and added a Southern Ocean.

Five or Seven

Now, according to the National Oceanic and Atmospheric Association, you have a choice Seven Seas or Five.  If you like the familiarity of seven, include: North Pacific, South Pacific, North Atlantic, South Atlantic, Indian, Arctic, and Southern Oceans. If you go for a simpler set of five, ignore the north and south divisions of the Pacific and Atlantic, and include: Pacific, Atlantic, Indian, Arctic, and Southern.

 Whales in the Seas

It turns out that in my short list of four whales, one is not so global. Grey whales are limited to the Northern Pacific. Also, they had once been in the Northern Atlantic but that population has now gone extinct.

The other three whales, Blue, Sperm, and Humpbacks, are worldwide travelers that do visit the Seven Seas. In general. The specifics and details do differ with each whale and its seasons. For example, they vary in their visits up to the edge of the Arctic icepack, and male and female sperm whales migrate quite differently. Humpbacks may be reclassified into 14 distinct populations.

These details will be vital for wildlife research and  conservation efforts. Meanwhile, I’m glad to be able to keep the poetic image of some great whales sailing the Seven Seas.