Became the owner of a modern yacht (an Oyster 485) in 2001. The boat was christened as a Canadian vessel, and named s/y Katharsis, meaning “purification”.

After his first year in the Mediterranean, Mariusz Koper decided to circumnavigate the globe. For reasons of the skipper’s professional obligations, the cruise was divided into 23 legs. Katharsis, with Mariusz and a rotational crew, visited 40 countries, logging 39,000 nautical miles. The Atlantic was crossed from Cádiz to the Caribbean via Canary Islands, Cabo Verde, Brazil’s northern coast, the French Guiana, and Trinidad and Tobago. When in the Caribbean, Koper joined the Oyster British Virgin Islands Regatta 2004. The Pacific Ocean was crossed from the Panama Canal to Australia, via the Galapagos, the French Polynesia, Cook Islands, Tonga, New Zealand, Fiji, Vanuatu, and the New Caledonia. After a visit to Indonesia and a lengthy stay in Thailand, s/y Katharsis set out for the Indian Ocean to return to Greece via the Gulf of Aden (famous for its pirates) and the Red Sea. After seven years, in May 2009, Mariusz Koper and s/y Katharsis reached Athens, thus closing his loop around the world.

In August 2009, Mariusz Koper collected his new yacht from the shipyard: an Oyster 72, christened Katharsis II in Gdańsk. The new 72-footer and her crew faced their first major challenge during the Atlantic Rally for Cruisers (ARC 2009). Katharsis II crossed the Atlantic as the first in her class, proving the braveness of the vessel and her crew.

The strong yacht and a proven team justified another challenge: a cruise around both Americas with a visit to Antarctica. Polar regions began luring Mariusz already during his first visit to Spitsbergen in 2001. The Tahiti-Ushuaia (Argentine Patagonia) crossing included the Easter Island, the roaring forties and the furious fifties, and rounding Cape Horn. Leaving Cape Horn, Katharsis II set off across the Drake Passage for the South Shetland Islands and the Antarctic Peninsula. Crossing the Antarctic Circle became the next goal of the expedition. Having successfully completed all plans, s/y Katharsis II returned to the canals of Patagonia.

The South America loop closed in the Caribbean in November 2011. Following another season in the Caribbean and Central America, the yacht set off north towards the Arctic, targeting the North-West Passage. Katharsis II sailed from Saint John’s, Canada, in early July 2012. The crew were offered a taste of icy adventure in Greenland already, with Katharsis II icebound in the harbour of Ilulissat. Despite the global warming, eastern parts of the Canadian Arctic remained icebound until early August 2012. In the course of the passage itself, the yacht encountered pack ice of major density several times. Katharsis II was the first yacht with an entirely Polish crew to cross Victoria Strait, pushing through an ice field 120 nautical miles long. Katharsis II was also the first yacht to cross the navigationally trying Bellot Strait in both directions. On August 30th 2012, in severe storm conditions, the vessel reached the Bering Strait, thus completing the North-West Passage. S/y Katharsis II ended its circumnavigation of both Americas at the Galapagos Islands.

Cruises to polar regions apart, Mariusz Koper frequently chooses warmer venues seldom picked by sailors, such as the Austral Islands of the French Polynesia, Samoa, Vanuatu, Solomon Islands, Papua New Guinea, and Palau. The cruise around New Zealand in early 2014 and participating in the 70th Rolex Sydney-Hobart Race were a major challenge as well. The Race remains among the most demanding regatta routes with an abundant record of dramatic events. Katharsis II arrived at the finishing line in Hobart in December 2014 as the first yacht with an entirely Polish crew attending the race. In Corrected and Elapsed Time terms, the result surpassed that logged by Wild Oats IX, an eight-time regatta champion.

S/y Katharsis II‘s third polar expedition took the yacht to the Ross Sea, open to navigation for no more than two months each year. The voyage began in Hobart, Tasmania, in January 2015. This had been the greatest sailing challenge for the yacht and her crew at the time. Antarctica was bound with the greatest ice field known in the history of the region’s research. The western approach to the Ross Sea did not open in the course of that austral summer.

Katharsis II pushed through the pack ice several times, to finally enter the Ross Sea as the first vessel with an entirely Polish crew. The goal of the expedition was to reach the Bay of Whales; it was achieved. On February 6th 2015, at 0415 Polish time, Katharsis II became the first yacht to enter the Bay of Whales – a deep indent in the Ross Ice Shelf. A severe storm and dense drift ice made it impossible to land on The Barrier. Yet Katharsis II made it further south than any yacht before, reaching 78°43’.566S and 163°43’.806W.

In 2016, Mariusz sailed the Indian Ocean from Indonesia to Cape Town, via Thailand, the Maldives the Seychelles. He sailed the final leg – over 3,000 nautical miles non stop from Victoria, the Seychelles to cape Town, the Republic of South Africa, with Hania Leniec only. This was not their first voyage in a crew of two. Previously, they had sailed from Tahiti to Samoa via Austral Islands and Cook Islands, and around the North Island of New Zealand. Sailing these waters with a crew of two aboard a 60-tonne yacht is a particularly demanding task.

Until now, Mariusz Koper has logged a total of 138,000 nautical miles, 92,735 of which aboard s/y Katharsis II. He visited 57 countries.