Celebrating women who map the world's oceans

 

World Ocean Day, June 7. Despite all the gendered (and racist) obstacles, women cartographers of the world's oceans have indeed made a contribution. World Ocean Day is a good day to remember them, including:

• Penelope Steel
• Marie Tharp

On June 7 2025 Greenwich's National Maritime Museum UK re-opens its new Ocean Court display area featuring the radical Spilhaus World Ocean Map projection. NMM

 Created in 1942 by oceanographer Athelstan Spilhaus, the projection (see pic) shows just how central the ocean is. 

I will be celebrating Spilhaus's vision. I'll  also be raising a glass to his many overlooked female predecessors and counterparts who have informed us about the world's oceans.

PENELOPE WINDE STEEL IN 1803-19

Jamaican-born Penelope Steel (c1768-1820), a woman of colour, was a success in the field over 200 years ago. 

Penelope seems to have engraved, as well as overseen map production and sales, from 1803 to 1819. Her charts weren't a radical challenge to the standard Mercator projection, like Spilhaus's. 

But they were so useful and accurate that the Admiralty supplied the fleet with these aids. Ironically, this daughter of an owner of enslaved people created maps that would have been used by naval ships fighting the slave trade in Caribbean waters. 

Penelope Winde Steel was the mother of five. Her own mother, Sarah Cox, was a freed negro slave', possibly a 'mulatto'. Sarah partnered a wealthy white merchant, judge, and slaveowner. He made Penelope (their natural daughter) one of his heirs.  

Penelope, a wealthy Afro-Caribbean woman, became successful in London partly because she was working in collaboration with three successive husbands. Her first, who she married in 1786, was David Steel. He inherited a nautical publishing and bookselling business. It might also have been useful that her (mixed-race) half-brother and his wife were London merchants; they could network. 

 MARIE THARP IN 1950s

In the 1950s oceanographic cartographer Marie Tharp (1920-2006) produced the revolutionary first map of the ocean floor. (See pic, above).

The American accidentally got into the profession partly because of WW2 shortages of experts in petroleum technology. Her father had given her some early informal training. 

She collaborated for decades with geologist Bruce Heezen. (Both are pictured).

WOMEN'S CONTRIBUTION

Earlier women were not allowed much power actually on ships. Indeed, as a woman, Marie Tharp was not allowed on ships to do her fieldwork. 

But women cartographers certainly enabled well-informed voyaging. I feel so aware of what more could have been done, had there been fair DEI opportunities for women who wanted to chart the oceans.

WANT TO KNOW MORE? 

# About women in maritime 

• Lloyd's Register Foundation Heritage Centre, Rewriting Women into Maritime initiative.RWM

# About Penelope Winde and her business 

• Penelope
• Susanna Fisher, The Makers of the Blueback Charts, A History of Imray Laurie Norie & Wilson, 2001.

# About women cartographers including Marie Tharp  

• https://en.wikipedia.org/wiki/Category:Women_cartographers
• women cartographers
• Tharp and others

# About slavery and mixed-race Jamaicans in British history, including Penelope's family 

• Jamaicans
• Winde