I think I know where this is going, and you're going about it all wrong.
You see, it would have to weave the coconuts together with saliva and fiber strands from the husks, like a floating nest-raft. Then it would have to ride the southbound East Australia side of the south Pacific gyre to the Antarctic circumpolar, get off at the northbound Benguela side of the south Atlantic gyre, cross west on the equatorial currents, and catch the northbound Gulf Stream side of the north Atlantic gyre, and bear left at the North Atlantic Drift. Then it would have to bear right at the Outer Hebrides, shoot between Orkney and Shetland, and try to make landfall at Norfolk. It could raise its wings in favorable winds, or flap around a bit in still air. Certainly doable for an experienced seabird.