The ship lost its cargo in December during a storm in California.
30,000 Nike basketball shoes ended up in the sea and are gradually making their way north.
Curtis Ebbesmeyer is an oceanographer who tracks currents in the sea by studying what gets washed up where.
Not in pairs
He's calculated the trainers moved more than 450 miles in a month - up to 18 miles a day.
He says: "These Nikes have only been adrift a few months. All 33,000 are wearable.
"Unfortunately, they weren't tied together in pairs so they'll all have to be put together with their mates.
A Nike spokesman says beachcombers who find soggy shoes can send them to the firm for recycling.