If you ask Pam Burridge what she sees when she looks at this black-and-white photo, she'll give you a distinctly technical description: "I see her riding a board eight-foot-six long and really difficult to ride."

The fact that the photo was taken in 1911, and the surfer is a young woman, doesn't faze Burridge, a surfing world champion.

"I just see the pure joy of her trying to keep with the flow, just riding the wave, just loving it and feeling it — and the skill."

Burridge, who is recognised as a pioneer of women's surfing, knows exactly how much of her career is due to the woman in the photo: Isabel Letham.

Letham is such an inspiration, in fact, that Burridge named her own daughter after her.

Confident from an early age

The only child of Scottish immigrants, Letham was born in Sydney in 1899, just two years before the Australian nation's own birthday.

She grew up near Freshwater Beach, one headland around from Manly, where 'surf bathing' — swimming in the ocean — was all the rage.

Letham eagerly adopted the popular pastime and was a confident swimmer and diver by the time she was a teenager.

Isabel Letham was determined to pursue surfing from an early age. ( Supplied: Warringah Library Service/National Portrait Gallery )

But this was Edwardian Australia — at a time when the archbishop of Sydney was advocating for sex-segregated beaches — so a girl needed more than just physical courage to flout the gendered rules of propriety.

Fortunately for Letham, her mother was an adherent of the first wave of feminism that was washing over the world.

"I had been brought up to stand on my own two feet at a very early age," Letham later said in a radio interview.

"I was quite determined I was going to ride a surfboard."

Letham's builder father initially objected, but, faced with his daughter's determination, she says, "he changed his mind".

He made her a beautiful board out of redwood.

A modern woman

When Hawaiian swimming champion and Olympian Duke Kahanamoku visited Freshwater to give a demonstration of wave riding in the summer of 1914-15, he selected Letham to partner him in the spectacle of tandem surfing.

While she later admitted to being scared out of her wits — "I thought I was going to disappear altogether" — the teenager proved herself to be Kahanamoku's equal.

She became a local hero and left school at 16 to work as a swimming instructor, saving enough money to pursue her goal of moving to California.

She stayed for around 10 years, teaching swimming at the University of California, but returned to Australia after falling down a manhole and sustaining a terrible injury.

As an independent-minded, risk-taking girl with a propensity to push the physical and social limits that constrained women's activities, Letham was both before her time and exquisitely of it.

As historian Dr Anne Rees, postdoctoral research fellow at La Trobe University, explains: "This is the time when we start to see the emergence of the figure known as the modern woman or the modern girl, later known as the flapper in the 1920s".

Having won the vote in 1902, women were looking for other barriers to tear down.

"They really wanted to break through into other terrains that had been dominated by men, including the professions, but also sports and different forms of leisure activities," Dr Rees explains.

"A huge way in which women asserted their modernity, their independence, their freedom was through new forms of bodily movement and display.

"Swimming and surfing is very bound up in these new horizons that [were] opening up for women in the early 20th century."

Letham was not a curiosity in her own era: she was a celebrity.

Dr Rees argues that her "bold taking up of space" offers a counter-narrative to the iconic figure of the Anzac, which is more readily associated in Australian historical consciousness with this era.

To Dr Rees, the photograph of Letham riding that wave represents the "last hurrah for progressive Australia that existed in the 15 years or so between Federation and WWI, before the militarism and the death and the grief of WWI starts to take hold".

'Puberty Blues was not a fantasy'

But it's not only mythological shifts in awareness that sidelined the memory of Letham and her achievements.

Surfing culture itself developed in a way that largely blocked women's participation for much of the 20th century.

Women were denied membership to surf life-saving clubs, and were harassed and intimidated in the water.

In the 1960s, according to Graham Cassidy, former president of the Australian Professional Surfing Association, "women were despised in the water".

Pam Burridge is a legendary surfing champion, who drew inspiration from Isabel Letham. ( Supplied: Pam Burridge )

Male surfers, he says, "went out of their way to run over women surfers, ride over the top of them, make sure they didn't come out again".

"Puberty Blues was not fantasy," recalls Pam Burridge of her early years of surfing in the 1970s, "it was fact".

By the end of that era of sexual and social liberation — which was powered in a large part by second-wave feminism — women had won a grudging respect in the water.

In the 1980s, argues surfing journalist Jock Serong, greater competition and professionalism opened the sport up.

"Now we've reached a point where surfing has reached its tentacles into so many different parts of Australian society that surfing is almost an aspect of people's ordinary health or fitness," he says.

"It's become ubiquitous."

Inspiring a new generation

Watching women grab a board and paddle out the back is no longer a novelty, a spectacle or a threat.

But female surfing champions like Burridge, Pauline Menzer and Stephanie Gilmore have not forgotten the role models of the past, or the part they played in supporting young female surfers through the tough times.

Letham was present to watch Burridge win the inaugural Australian women's surfing championship in 1980.

"Most Australian surfers would have an understanding that [Letham] is this formative figure in our history", Serong says, "and it's interesting that other surfing nations don't have a significant early pioneer of the sport".

Letham died in 1995 at the age of 95, 80 years after she stood on the shoulders of Duke Kahanamoku, a towering figure in sports history.

As she once told Burridge, while the two sat looking out to sea, watching the waves break, and reform, and break again: "It's the big stuff I'm interested in."