[Bear_in_RoseBear]

The article indicates it took him 6 hours. I wonder if the tide was helping him at all, perhaps pushing him in?

[Sam Cree]

I'm not familiar with the currents between the Isle of Wight and Hampshire, but normally they run parallel to coastlines, though once you get near the beach the rise and fall can deliver or remove objects. Todd swam into a river, and tide definitely flows into and out of rivers. The tide as it goes upstream is called a tidal bore. But I doubt that the bore would reach to the island near where he fell overboard.