The flotsam from last year's earthquake and tsunami in Japan might span nearly the width of the Pacific, says a researcher and advocate for garbage-free oceans.

Because of marine currents, though, most of that 1.5 million tonnes of debris may stay at sea and never wash ashore on North American beaches.

Harley-Davidson motorcycle has already washed ashore in Haida Gwaii off the B.C. coast, and a massive dock turned up in Oregon. But Marcus Eriksen of the California-based 5 Gyres Institute and 11 other crew decided to see first-hand what's still churning in the Pacific, the CBC's Curt Petrovich reports.

Sailing from Japan to Hawaii, at one point they found a piece of debris every three minutes. A propane tank, a chunk of a fishing boat, even a piece of flooring from a Japanese home — divers found all that and more just below the water's surface.