Time agents Ross Murdock and Gordon Ashe, aided by a Polynesiian girl and her team of telepathic dolphins, probe the mystery of the sea-planet men have named Hawaika.
Andre Alice Norton (1912-2005) was an American science fiction and fantasy author (with some works of historical fiction and contemporary fiction) under the noms de plume Andre Norton, Andrew North and Allen Weston. Norton published her first novel in 1934, and was the first woman to receive the Gandalf Grand Master Award from the World Science Fiction Society in 1977, and won the Damon Knight Memorial Grand Master Award from the Science Fiction and Fantasy Writers of America (SFWA) association in 1983.
Andre Norton. Wikipedia.