By Sumayya
Polish endurance athlete Bartłomiej Kubkowski secured a monumental place in open-water sports lore by successfully navigating a continuous 55-hour marathon swim entirely across the unpredictable Baltic Sea.
Kubkowski established himself as the premier individual to successfully cross the brutal 100-mile expanse stretching from Kåseberga, Sweden, directly to the coastal shores of Dziwnów, Poland, entirely unassisted, per reports from SwimSwam contributor Keith Dunlap.
The monumental athletic feat successfully generated over $200,000 in vital financial resources for the Polish-based humanitarian organization known as the Cancer Fighters Foundation, according to details provided by EuroNews correspondent Katarzyna Kubacka.
This grueling expedition represented Kubkowski’s fifth career endeavor toward cementing this world milestone.
During his fourth campaign, emergency personnel were forced to extract him from the open water after the swimmer abruptly blacked out from severe physical exhaustion roughly seven miles out from the final Polish coastline in 2025, according to historical data from Dunlap.
To maintain his official unassisted athletic status throughout the crossing, Kubkowski received specialized nutritional fluid rations and food supplies via an extended feeding pole maneuvered from an accompanying escort vessel, completely avoiding any physical contact with the hull or crew members during the entire physical transition.
Environmental obstacles remained severe, with open water temperatures plunging down to a chilling 60 degrees Fahrenheit over the course of the marathon, causing Kubkowski to endure vivid hallucinations as he battled severe sleep deprivation during his final miles toward shore, according to additional reporting by Kubacka.
Available media footage documents a completely drained Kubkowski hoisting himself out of the surf, managing to stand entirely under his own physical strength on the beach before medical professionals quickly transported him to a nearby medical clinic for comprehensive evaluation, as detailed by Kubacka.
