Wagner Hernandes escorted Irish marathon swimmer Owen O’Keefe on a 40 km cross-border swim of the Río de la Plata between Colonia del Sacramento in Uruguay and Punta Lara in Argentina. His 15 hour 14 minute crossing was the 44th overall success and the first crossing by a swimmer from Ireland.
Río de la Plata (English: River Plate) is the wide estuary formed by the confluence of the Uruguay River and the Paraná River on the border between Argentina and Uruguay. It is a funnel-shaped indentation on the southeastern coastline of South America; it forms part of the border between Argentina and Uruguay.
O’Keefe tells his story, “In 2024, after almost 10 years of kayaking and crewing, you’d think he’d know better, but when I asked Wagner if he would be my sole crew member for a 40 km swim from Uruguay to Argentina, he didn’t hesitate to say yes (maybe it was better than another 5 years of listening to me talk
about this swim).
Fast forward through a year of training, including him sitting through another Cork Distance Week and crewing for a two-way Windermere as a training swim, we landed in Buenos Aires in December 2025. There began the usual process of getting used to a strange place, while obsessively refreshing Windguru and trying not to annoy the swim pilot too much.
A week later, I get a text from the pilot that there is the possibility of swimming early on Wednesday morning. The forecast is far from ideal, Force 4s for most of the day, but at least they should be at our back, and the other three swimmers on this tide have said no. They wouldn’t normally go out, but they believe in my experience, and I’m not going to get a better day, so we decided that we need to go with it as this will be our only opportunity. So, within 15 minutes, we have the noon ferry to Colonia and accommodation there for the next two nights booked, and within an hour we’re waiting for our taxi to the port. Luckily, I was actually organized enough to have a bag packed to leave at short notice.
Things get off to a great start when what should be a 15-minute taxi journey to the port started with 30 minutes to get to the corner of our block, so I have my first meltdown thinking we’re not going to make our ferry. Thankfully, we did make our ferry and had a smooth crossing to Colonia and stress-free arrival at our beautiful house in the heart of the UNESCO World Heritage old town. Colonia was a delight. I managed to not let the vastness of the river or raging wind get to me too much.
The following day, we got everything ready, had a meeting with the Open Water Argentina crew at the yacht pier and a briefing with International Marathon Swimming Hall of Fame Honoree Damián Blaum who gave us excellent advice about how I should approach the swim. I would not have been successful without his words. With nothing left to do but rest, a path was cleared in my mind for the crippling doubt to rush to the fore. The enormity of what lay ahead suddenly hit me and I had a complete meltdown, ‘What in God’s name was I thinking signing up for this? There’s no way I can see myself even getting halfway. How selfish of me to drag Wagner through all of this and create all this expectation, and for what, if I have no chance of completing it?’ It was probably the worst I have been before any swim, but he wasn’t phased and talked me out of my panic.
After about an hour’s restless sleep, it was time to head down to the pier for 3:30 am. The wind was brisk to say the least and although the air was 19°C it felt like 5°C. Two boats awaited us, one rigid boat with a small canopy and very smelly – the swim coordinator, pilot, observer, and doctor would be on this, the other a tiny RIB with no shelter – Wagner would be on this one with a skipper and a lifeguard. I got changed and greased up in what little shelter was to be had on the pier and headed for the rib, whose engine would not start. I sat on the edge, frozen to the bone and silent, watching Wagner get all of the gear organized on board. My head was in a very
bad place, but he knew that seeing him carrying on like it was any other swim would reassure me, and that once he got me into the water I’d be okay.
The boat eventually got going and we headed around to the start. The crew gave me the thumbs up and I slipped off the rib and into the dark waters of the Plate – the relief to be out of that cold wind and into the warm water was unreal. The water felt and tasted nice, I swam into the rocks for the start and off we went – and it was beautiful. As we got further from the shore and more exposed to the wind, the water got rougher and I started missing strokes and breaths. My mandatory tow-float kept banging the back of my head and going over my shoulder, but I still felt more sorry for the three-man crew of the rib; they were being thrown all over the place, and soon would be under the huge Pampas sun with no shelter.
After a few feeds, I saw Wagner throw up over the side – his first time ever getting motion-sick.
As he didn’t initially take the tablet that was offered to him, he was warned that if he threw up a second time, they would have to call off the swim due to the risk of him becoming dangerously dehydrated with no prospect of a quick rescue. He took the tablet, and not long after, the lifeguard, who had taken it, also threw up. Mati lives at the river’s edge and spends his days out on the water, so it was a measure of the conditions that this was also his first time being sick out there.
Luckily, that was the end of the throwing up from any of the crew. I plodded on through the waves, one arm in front of the other, from feed to feed, hour after hour. Wagner and the rest of the crew never took their eyes off me and were full of positivity on every feed.
After 12, 13, 14 hours, it became clear that an expected change in the direction of currents was not going to materialize, so we were heading much further east than planned. This meant having to adjust our course and significantly slow our forward progress. This was extending an already very long day for the crew, but there was no complaint from them – they were determined to give me every chance to finish the job.
After 15 hours 14 minutes, and with the sun going down, we finally landed at Punta Lara, Argentina, to the elation of myself, both crews and the coast guard, who had escorted us the last few kilometers. When I got back on board, Wagner showed no sign that he had just spent a very long and uncomfortable day on a tiny boat with no food or shelter under the mid-summer sun and with a significant language barrier between himself and the other crew – he just got on with the usual post-swim routine.
Unfortunately for him, it didn’t end there. The following days were busy with trips to the coast guard office near Tigre to stamp our passports, a radio studio in La Boca for an interview with a station connected with my family, and a visit to the Irish Embassy to meet the Ambassador and Consul. He needed a lot of patience to spend his holidays on the likes of that.“
Hernandes has escorted O’Keefe on a number of marathon swims, both domestically and internationally.
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