"Terthinus, the King of the Malasp merfolk, found a terrible new god at the bottom of the ocean floor. He took it back to his people, and fell worship was done to it. They prayed that all of the wealth of the air dwellers who skimmed across the surface of the seas would fall into their lands. This prayer was granted, after a fashion."
One of several parallel explanations on the Closing discovered by my Vithelan heroes, based on snippets in the Guide and "Men of the Sea".
Any idea what it is? A strange side effect of Zzabur's spell? The sunken remnants of the Boat Planet? Or something else entirely?