wonky hole

noun1

1. •
   (Australia) A type of undersea hole or spring on the Great Barrier Reef in Australia, out of which emanates fresh water that has flowed underground from the land.

   • It was local fishermen who made the most startling seafloor discovery. Something unknown was snagging their nets and nearly capsizing their boats. And they called the mystery – wonky holes. — Australian Broadcasting Commission Catalyst program, 18 May 2006 (transcript)