The Lazarus Effect (The Pandora Sequence 2)

A world of water

In The Jesus Incident, Frank Herbert and Bill Ransom introduced Ship, an artificial intelligence that believed it was God, abandoning its unworthy human cargo on the all-sea world of Pandora. Now centuries have passed. The descendants of humanity, split into Mermen and Islanders, must reunite because Pandora's original owner is returning to life.