The Spilhaus Endless Ocean Map Projection

Katarina Samurović


We greatly depend on our oceans. Obviously, we depend on them for food, transportation, and medicine. A less known fact – all of us depend on ocean-produced oxygen, which makes up more than 50 percent of all of the oxygen in the atmosphere. 

Despite all of that, human thinking and planning are mostly land-oriented – and so are our maps.

On most maps, oceans are just passively surrounding the land. In the process of fitting the oceans into the classic projections, they get seriously distorted. As a consequence, users fail to realize the actual size of the oceans, as well as their interconnectedness.

Just by looking at an average map, most people will not be able to conclude that the oceans take up 71% of the Earth’s surface, and that there are no interruptions between different oceans – basically, there is just one big “Earth sea.”

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An Ocean Map Projection

However, in 1942, a South African meteorologist, oceanographer, and inventor Athelstan Spilhaus tackled this historical injustice and created the world’s first fully ocean-centered map projection

The Spilhaus ocean map came about as a side project of the scientist’s most famous invention – the bathythermograph, a deep-water thermometer capable of recording depth and the temperature underwater, including the changes caused by moving vessels – submarines.

A Combination of Hammer and Spielmann Projections

World ocean map (conformal; August Projection) from Spilhaus, 1942
World ocean map (conformal; August Projection) from Spilhaus, 1942

Essentially a combination of the Hammer and Spielmann projections, Spilhaus ocean map is an Antarctica-centered projection, and it is not accidental.. As you can see, Antarctica precisely the point from which Spilhaus could “stretch out” ocean surfaces in all directions without distorting them.

Except for Antarctica, other land masses on the map only represent the stripped-down borders of oceans. Therefore, the continents are quite distorted, especially Asia and the Americas. As an illustrative example, the poles of the map are placed in South America and China.

“Sacrificing” the representation of land was in this case worth it – it enabled Spilhaus to create the first map of Earth’s oceans, realistically sized and uninterrupted.

Much has happened since Spilhaus map was created and then forgotten. In the second half of the 20th century, our oceans have become increasingly troubled, and sadly, the negative trend continues today.

The global temperature rise is causing all kinds of imbalances, including the dreaded deoxygenation; excessive carbon-dioxide that the ocean is sucking the atmosphere is causing acidification; freshwater input from the melting in Greenland is disrupting ocean circulation.

With direct human pressures such as pollution, overfishing, and surface runoff added, it is clear that Earth’s ocean systems are facing unprecedented hardships. The fear is that, no matter how enormous these systems are, their balance is going to be damaged beyond recovery if measures are not taken to reverse the trend.

Enthusiasts hope that re-discovering Spilhaus map is one of the ways to bring more awareness to the issue.

By looking at maps and images of Earth’s surface, humans start to foster a sense of connection. It is difficult to sense responsibility and love for something you can’t really visually comprehend. Have you ever heard of the saying “Out of sight, out of mind?” Well,  it seems that the oceans have been out of our minds – and underrepresented in our cartography – for far too long.

Once a submarine detection device spin-off, today the Spilhaus ocean map might serve an even greater purpose. It may help to remind us that the Earth is not just “the green planet” – that actually, it is the clear ocean-blue that dominates our planetary home. We can’t afford to lose that clarity.

Spilhaus’ map projection featured in his map puzzle patent:


Spilhaus, A. (1942). Maps of the Whole World Ocean. Geographical Review, 32(3), 431-435. doi:10.2307/210385. Retrieved from

Spilhaus, A. (1983). World Ocean Maps: The Proper Places to Interrupt. Proceedings of the American Philosophical Society,127(1), 50-60. Retrieved from

World Ocean Map Poster (Spilhaus Projection). (1985). Science Scope, 9(2), 17-20. Retrieved from

Jacobs, F. 2018, “Finally, A World Map That’s All About Oceans.” Big Think.

”Athelstan Spilhaus“. Le Cartographie Blog (French).

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About the author
Katarina Samurović
Katarina Samurović is an environmental analyst and a freelance science writer. She has a special interest in biodiversity, ecoclimatology, biogeography, trees, and insects.