Mermaids – half sushi, half supermodel – lure love-starved mariners onto the rocks with their siren songs, or so believed the ancient mariners of the Mediterranean. Some thought the mermaids actually meant well, but (as Wikipedia puts it) "squeezed the life out of drowning men while attempting to rescue them."

In the annals of Hispanic seafaring, however, there is a record of one incident where maidens of the sea actually did rescue drowning marineros.

Before dawn on Sept. 30, 1609, the Spanish galleon San Francisco, dismasted and rudderless, was driven onto a reef during a fierce typhoon. En route from Manila to Acapulco, she carried 373 Spaniards led by Don Rodrigo de Vivero, governor of the Philippines.

Fortunately, helping hands pulled 317 of the half-drowned and hypothermic mariners from the surf. Imagine the survivors' amazement to discover their rescuers were a race of athletic, bronzed and bare-breasted women. Surely these must be mermaids!

In fact they were ama-san, the abalone divers of Iwawada, then a fishing village of 300 people 75 kilometers southeast of Tokyo, now part of Onjuku Town on Chiba Prefecture's Pacific coast. According to local legend, the ama-san warmed the frigid Spaniards with their bare bodies. One can well imagine how effective this must have been!

The village, far from wealthy at the time, immediately had twice as many mouths to feed. Don Rodrigo, however, lavishly praised the locals' hospitality in his journal over the month his crew spent in Iwawada.

The local daimyo, Honda Tadatomo, finally took the Spaniards inland to his castle at Otaki. From there they were sent to Edo to appear before the second shogun, Tokugawa Hidetada, son of Ieyasu. Eventually they were shipped off to Acapulco on the Western-style vessel the Englishman Will Adams famously built for the Shogun. (That, however, is another story.)

MEXICO EMBRACES THE MEMORY
Meanwhile, obscurity restored, Iwawada went back to the business of catching seafood, and the world beyond the village's green hills soon forgot about the rescue of the San Francisco's crew. But local memories persisted, if only because not much else happened for the next three centuries.

Not until the 1920s, in fact, did recollections of the San Francisco resurface elsewhere, and then only because Taisho Japan was looking to cultivate relations beyond the circle of Great Powers. In October 1928, the country erected a 17.5-meter obelisk above Iwawada to commemorate the event, in conjunction with moves to deepen relations with Mexico – Don Rodrigo's birthplace and the ship's destination. But since Mexico was a Spanish colony in 1609 and the galleon had sailed from Manila, Spain and the Philippines were included as well.

In protocol terms, this made for an odd quartet. But the Mexicans have taken pride of place by embracing the memory with enthusiasm that continued through the 400th anniversary celebrations in 2009. Fittingly, the obelisk now sits in "Mexico-koen," and Acapulco is Onjuku's sister city. The Spanish come along to the party like chaperoning aunties. And the Philippine flagpole is bare.

What was remarkable is that when the diplomats came out to unveil the commemorative shaft in 1928, just over the hill the ama-san were still diving for abalone in a manner virtually unchanged for over 300 years.

IMAGES OF JAPANESE FEMININE POWER
Not long after the obelisk went up, local sake brewer Yoshiyuki Iwase (1904-2001) began to photograph the unselfconscious ama-san at work and at play.

The earliest of his 50-or-so surviving images are from the '30s; the latest from the early '60s. Iwase shot his best work between 1945 and 1955 after his skill had matured, he had obtained the right equipment, and the ama culture was still intact. Over this period his photos earned recognition at home and abroad, winning the Rollei International Contest in 1949 and the Prime Minister's Prize in 1957.

As a Western male who grew up while graphic displays of flesh were still rare enough that National Geographic could seem risqué, I have to admit this body of work triggered a flashback frisson from boyhood. But these are way better than the "bare-bosomed African ladies" we used to marvel at.

Viewed with a more mature eye, Iwase's images provoke a realization that no one has ever shown us Japanese women like these bronzed, athletic females, unselfconsciously naked and covered with sand and salty sweat, muscles straining as they push a boat up the beach.

This is the polar opposite of a modern femininity that favors twee toilet slippers from Jiyugaoka boutiques, and a refreshing antidote to images fed to the West since the Meiji Era of Japanese women as fragile, submissive dolls.

Even more remarkable is how much more in common the Iwawada of half a century ago had with 1609 than with the present day. Apart from the divers' cotton shorts, there is not much in these scenes the shipwrecked Spaniards would not recognize. And yet many of these women can still be seen – fully clothed and much older – in the village today.

Before long, of course, sadly but inevitably, these obaa-chan will go the way of all mortals. But with Iwawada's beach now thronged each summer by bronzed, bikini-clad surfers, happily, this is still a place where fit females frolic in the waves. And back from the beach, near Onjuku Station, visitors can still catch a glimpse of the mermaids of yore.

Yoshikazu Iwase, the photographer's son, maintains a small gallery of his father's work at the family's sake brewery, Iwanoi (Tel: 0470-68-2034). While slaking your thirst with Iwanoi's finest – described by sake maven John Gauntner as "rich and layered" – be sure to visit the brewery's 400-year-old thatch-roofed office. Its main beam is reputed to be a timber from the galleon San Francisco.

John R. Harris is a speechwriter and freelance
journalist who lives deep in a forest in the green hills behind Onjuku.