Voyage to a New World — Tom Hatfield

It is about a young girl (in our timeline) who directs a sailboat filled with her mother and four other women, plus two men on a month-long odyssey to a small island in the South Pacific where humans are being transported off the planet to where? Other planets? A Parallel Universe? They will return after the human population on Earth has destroyed itself, and the planet - now named Gaia - has a chance to recover.