“Iconic” was the word of the day. As Australian and American swim stars gathered at Bondi Icebergs to observe the opening event of the three-day Duel in the Pool – an open water relay – adjectives flowed freely. It was an “iconic” event, said one swimming executive, at the “iconic” Bondi beach. “No more appropriate location than Bondi,” offered the state tourism minister, Ben Franklin. “Iconic.”

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Sport is prone to hyperbole, but this was probably fair enough. Australia v the United States, the two heavyweight swimming nations, head-to-head. Not at the Sydney Olympic Park Aquatic Centre (that comes this weekend), but at Bondi beach – the spiritual home of Australia’s aquatic culture, the nation’s very own swimming mecca. Not a duel in the pool but a battle from one end of Bondi beach to the other and back, and then out and back again – “four by almost 800 metres,” one event organiser quipped, noting the difficulties of setting up an exact “course” in the middle of the ocean.

Pool swimming is a sport defined by millimetres and milliseconds. It is a sport of certainty and finely-tuned preparations. As the sun rose over Bondi on Friday morning, there was none of that. The American and Australian teams conferred on details while perched on the beach steps, and last-minute questions were met by shrugs. It was apparent that both nations were entering the unknown.

“It’s pretty cool to be racing here at Bondi,” said Australia’s Kareena Lee, an open water bronze medallist at the Tokyo Olympics, as she limbered up on the sand. “A little bit different to what we’re used to!”

Australia’s four swimmers– Lee, Chelsea Gubecka, Kyle Lee and Kai Edwards – are all specialised open water swimmers, albeit more accustomed to racing 10 or 20 kilometres, not a mere 800m. The Americans went for a different approach, throwing their pool swimmers into the ocean. The Australians were acclimatised to the conditions – Edwards lives nearby and had been training at Bondi – while the Americans were better-suited to the distance. “I think it will be a fair playing field,” said Kareena.

“Bondi is such an iconic spot,” added Kyle (the first of a double-digit count for the “i” word during the morning). The quartet joked about sharks and mind-games with the Americans; fortunately, no great whites would be sighted. The waves rolled in, with 50 or so surfers spread across the beach, although the relay course was just beyond the breakers. “We would have loved some more chop,” Kyle said. The bigger the waves, the more pool specialists would struggle.

At Icebergs, swimmers from both nations rubbed shoulders with suits from the state government and its tourism agency, which is underwriting the event. Cody Simpson, the swimmer turned pop star turned swimmer again, snapped selfies with Australian swim legend Grant Hackett and young fans in turn. “This is an awesome way to start it off with the open water relay,” said Simpson. “This is probably one of the most iconic pool locations in Australia, if not the world.”

Hackett, serving as team captain for Australia this weekend, eyed the waves with a hint of desire. “I would have loved this,” said the now-retired three-time Olympic gold medallist. “Not many people know this, but I actually grew up more surf swimming than pool swimming. I wanted to be an iron man.”

Perched on the look-out above the picturesque ocean pool, Americans looked enviously at the locals swimming laps below. A few came up to say hello, clad in dripping togs and unsure what all the fuss was about.

“Australia has never beaten the United States at the Duel,” said Swimming Australia boss Eugenie Buckley. The rivalry was a regular feature of swimming calendar in the 2000s, when Hackett and co faced off against the American superstars, but there has been no Duel in the Pool on home soil since 2007. After a decade in the (relative) doldrums, the Australian national swim team – the Dolphins – are back, finishing neck and neck with the United States in the pool in Tokyo. This weekend, the Australians might claim their first head-to-head scalp.

But if the two nations’ swimmers were taking this weekend’s meet seriously, it didn’t show on Friday morning. After a hectic international calendar, most recently the world championships in Budapest and then, for Australia, the Commonwealth Games in Birmingham, “fun” seemed to join “iconic” as the words of the day.

“This is the fun part of swimming,” said American Annie Lazor, a short-course breaststroke world champion and Tokyo bronze medallist. “This is arguably the two best swimming countries in the world going head-to-head, but it’s such a nice opportunity to have – even though it’s a rivalry – a much more light-hearted competition.” The weekend’s action in the pool includes a range of atypical events: “broken” relays, “random” order medleys and, for the first-time in an international swim meet, an “integrated” relay featuring both able-bodied and para-swimmers.

Simpson chatted with his girlfriend, Australian swimming stalwart Emma McKeon, as the cameras lingered on the pair. One onlooker offered: “I just came to see Cody Simpson.” Fellow Dolphins regulars Kaylee McKeown and Mack Horton watched on, while the American team – mini-flags in hand, voices ready to cheer – took up the best spots on the look-out.

Pool swimming events are typically managed to the minute, but no-one seemed too perturbed as the designated 9am start-time slipped by. “Have they started yet?” someone asked at five minutes past, as the gathering looked enviously at one spectator to have remembered binoculars. Finally at 9.10am the race began, one swimmer from each nation leading off from a makeshift pontoon on the southern end of Bondi. “Iconic” was dropped again – perhaps this time ironically.

Someone took the lead, although – from such a distance, with no readily-identifying features – it was hard to know which nation had gained the early advantage. “Australia is always in front,” offered one member of the Dolphins. Fortunately another onlooker had a phone number for an official thought to be stationed the pontoon: “Are you on the pontoon? Are we in front?”

It transpired that the Australians were not in front. The US had made a tactical gamble – opening the race with two male swimmers, and concluding with two women. The Australians had gone for the reverse: woman, woman, man, man. The Americans built a steady lead, but would have to hold off the fast-finishing Australians. At one point the gap between the nations almost resulted in a mid-water collision; a fresh American swimmer hurtling towards a finishing Australian, only for the pair to narrowly glide by each other.

From the Icebergs look-out, Lazor surveyed the view. “It’s amazing,” she said. Lazor recalled how she and teammates had accompanied the open water relay team on a reconnaissance mission earlier in the week. “And we thought we’d jump in this iconic pool. I mean – it’s a bucket-list item, right?” Asked if more laps might follow after the race, Lazor demurred. “It was a little too cold for me the other day, and it’s a little chilly this morning.”

As Australia’s anchor swimmer, Kyle Lee, began his 800m leg, he faced a 17-second deficit. But he steadily ate it up. As Sydneysiders went about their day – surfers enjoying the morning waves, Icebergs regulars doing their laps, personal trainers working with clients in the background – the inaugural Australian Dolphins v Team USA swimming relay at Bondi beach went down to the wire.

“Let’s go Australia go the Aussies,” cheered the small crowd, as Lee surged home to narrowly win the relay. Half an hour later, having dried off and warmed up, and joined the remainder of the team tucking into a spread of pastries at Icebergs, the rising star of open water swimming summed up the event. “It was nice to do something different, at such an iconic place,” he said.