The 8,000-mile green voyage (by the seasick billionaire)

Money will get you a lot of things, including a 60-ft catamaran built almost entirely out of recycled plastic bottles, held together with organic glue made from cashew nuts and sugar cane. But the joy of stepping on to dry land after navigating such a vessel on a gruelling 128-day journey across the Pacific is one of those things that money simply can't buy.

Yesterday David de Rothschild, scion of one of the world's richest banking fortunes, could finally put the regular bouts of chronic sea-sickness behind him as he and his five crew mates birthed their unusual vessel, the Plastiki, in Sydney Harbour after four months at sea.

De Rothschild, who set off from San Francisco in March, was hit particularly hard. The billionaire environmentalist admitted spending much of the opening stages of his odyssey bent over the side of his ship's recycled hull before his sea legs finally returned and he could keep a meal down.

But as the crew struggled to manoeuvre the notoriously tough-to-steer vessel into port outside the Australian National Maritime Museum yesterday, the 31-year-old joked that they had one final challenge to complete – parking. "This is the hardest part of the journey so far – getting it in!" he yelled from the boat.

It was the end of a remarkable journey which had been made to raise awareness over the huge levels of plastic waste in our oceans and saw the Plastiki's crew having to battle near hurricane winds, temperatures of 38C, a diet of rehydrated food and that scourge of land lubbers and hardy sailors alike – sea sickness.

De Rothschild came up with the idea after reading a UN report on plastic pollution in the world's oceans. A poster boy for the modern environmental movement, he prides himself on using none of his family fortune to fund his eco-adventures. He named his ship after the original Kon-Tiki voyage in 1947 by Norwegian explorer Thor Heyerdahl who sailed 4,300 miles on a raft made from balsa wood and other materials from South America to the Tuamotu Islands in French Polynesia in the Pacific Ocean.

Despite the unusual materials used in its construction, the ship held up remarkably well despite meeting a series of major storms in the Tasman Sea. At one point the crew had to negotiate winds of 60 knots, 12 knots less than a hurricane. Recalling the storm in a video blog, De Rothschild said: "I remember being woken up by Mr T [co-skipper David Thompson] shouting 'all hands of deck'. I'd always been apprehensive of the Tasman Sea and what we were going to face. This was kind of like my own worse nightmare coming to fruition."

The route took the vessel close to the Great Pacific Garbage Patch, an enormous mesh of plastic and chemical sludge that circles a series of gyres in the heart of the ocean. The vortex is thought to be up to six times the size of Britain, containing millions of tonnes of non-biodegradable rubbish that wreaks havoc with marine and bird life.

Some of the crew members had to wrestle with more than just the day-to-day discomforts of living in a cabin of just 20ft by 15ft as it ploughs through 8,000 miles of ocean. Jo Royle, the ship's captain, was the only woman on board and said she was looking forward to spending some time with less hirsute companions in the coming weeks. "I'm definitely looking forward to a glass of wine and a giggle with my girlfriends," she said.

Vern Moen, a filmmaker who was documenting Palstiki's voyage, had a particularly emotional end to his journey. He was greeted by his newly born son on arrival in Australia. He was able to watch the delivery of his child on a grainy internet connection using Skype. "It was very, very surreal to show up on a dock and it's like, 'here's your kid'," he said.