Unfathomable: 20 Wild (But True) Stories About the Ocean

by Mary Boone, Max Temescu (Illustrator)

Wrestle an octopus, swim through a sunken city, and discover 20 incredible-but-true stories from our unbelievable—and unpredictable—oceans. From acclaimed nonfiction writer Mary Boone comes an illustrated look at the fascinating stories that take place under (and above) the sea.

Did you know you can survive being swallowed by a whale? Or that octopus wrestling used to not just be a pastime but also an actual sport? Or, that once a town in Oregon didn't know what to do with a whale carcass that washed up on their beaches, so they...BLEW IT UP?

As strange as it sounds, those stories are 100% true. And the sea holds more secrets. Grab your snorkel and dive into 20 incredible-but-true tales of survival at sea, sunken treasures hiding under the ocean's surface, jellyfish that live forever, and so much more.

From accomplished nonfiction author Mary Boone comes an illustrated look at the unfathomable tales our oceans have to tell. Each chapter contains one story, with interview quotes and hands-on research that uncovers the science and history behind the event. You’ll get facts AND more!

A Junior Library Guild Gold Standard Selection

Genres: Nonfiction

192 pages, Library Binding

Published February 17, 2026

Reviews

[Teresa Reads · Rating 4 out of 5]

I like this book. I really like how it tells you about all kinds of things about the ocean, not just the creatures that live there. One of my favorite parts was learning about the treasures that people find in the ocean. I think you would have to be brave to go searching for treasure under water, but if you find jewels, then I guess it would be worth it. I liked the other stories too. The only thing that would make the book better is to have actual photos and not just drawings. Kids want to see the real stuff. (review by Easton, 5th grade)

[Erin Dealey · Rating 5 out of 5]

Mary Boone's active, inviting, clever text and the fascinating facts of Unfathonable make me think of another high-interest, middle grade: Two Truths and a Lie (Ammi-Joan Paquette & Laurie Ann Thompson/ Walden Pond)--only Boone's focus is our ocean and ALL the stories are TRUE. In addition, each story is written with awe and underlying respect for the ocean and our environment. I can see this being a favorite in classrooms and libraries. Lots to love here.