Flushing is where the Swallows' unplanned sea voyage in Goblin ends up, as described in We Didn't Mean to Go to Sea. Daddy's cross-channel ship is, fortuitously, about to depart for Harwich as Goblin and her crew are being piloted into Flushing by the Flushing Pilot.
Real prototype[]
Vlissingen, still often called Flushing in English, is an important port in the Netherlands.