Speaking to the media, de Rothschild said he hoped the Plastiki would highlight, in an enlightened way, the growing problem of plastic in the world's oceans.
"It doesn't need to be po-faced, it doesn't need to be a chore. It can actually turn out to be a great adventure and that's hopefully what the Plastiki has done," he said.
De Rothschild, 31, said the idea for the journey came to him after he read a United Nations report in 2006 that said pollution, and particularly plastic waste, was seriously threatening the world's oceans.
He decided a good way to prove that rubbish can be effectively reused was to recycle some of it to construct a boat.
The boat is almost entirely made up of bottles, which are held together with an organic glue made of sugar cane and cashews, and includes other materials too.
The mast, for instance, is recycled aluminium irrigation pipe.
The Plastiki, named after the 1947 Kon-Tiki raft sailed across the Pacific by explorer Thor Heyerdahl, is fully recyclable and gets its power from solar panels and windmills.
The crew of the Plastiki, an 18-metre catamaran that weathered fierce ocean storms during its 12,000km at sea, left San Francisco, California on March 20, stopping along the way at various South Pacific island nations including Kiribati and Samoa.
During their 128-day journey, the six-member crew lived in a cabin of just 6m by 4.5m, took saltwater showers, and survived on a diet of dehydrated and canned food, supplemented with the occasional vegetable from their small on-board garden.
Along the way, they fought giant ocean swells, 62-knot winds, temperatures up to 38 degrees Celsius and torn sails.
Although the team had originally hoped to recycle the Plastiki, de Rothschild said they are now thinking of keeping it intact, and using it as a way of enlightening people to the power of recycling.