"Into the Planet is a breathtaking thrill-ride into a deeper world that exists within this one. Few people have witnessed the sublime beauty of labyrinthine underwater caves or the inside of an iceberg - to venture in for even a glimpse is to put your life at risk - but Jill Heinerth knows these realms intimately. She is the ultimate guide, and her courage and heart are as evident in her writing as they are in her groundbreaking explorations. Clear your schedule if you pick up this book, because you will not be able to put it down." (Susan Casey, author of The Wave: In Pursuit of the Rogues, Freaks and Giants of the Ocean)

"One sentence into the phenomenal life story of Jill Heinerth and you'll be hooked. Be prepared for a wild, wonderful and deeply inspiring journey into places few people get to know, let alone experience. Into the Planet is a beautifully crafted memoir that inspires us all to defy limits imposed, connect us to this precious planet, and follow our passions in life." (Clara Hughes, six-time Olympic medalist and author of Open Heart, Open Mind)

"I can guarantee you one thing: Jill Heinerth will not look back on her life with any regrets about a lack of bravery or passion. In this gripping, life-of-gusto story, we plunge into Heinerth's eccentric world of death-defying caves, and into her inner sanctum forged by the thrill of discovery. I read wide-eyed, page after page." (Diana Nyad, long-distance swimmer and author of Find a Way)