There is a lifeguard in this book, and he spends most of it trying to get a class of children out of the water. He loses. Ms. Frizzle drives the bus straight in, the whole thing turns into a submarine, and the class ends up on the bottom with him still in tow.
What they cover on the way down is a lot: the shape of the sea floor, a coral reef, the animals and plants living on it, and hot water vents. Joanna Cole wrote it and Bruce Degen drew it. Picture book, cartoon panels, hand-lettered reports around the margins the way the series always does it.
The science it actually teaches
Our Stealth Science shelf carries this one for a single page, and I will get to it, but the frame around that page matters first. The ocean is organized by depth, and depth is the thing this book teaches best.
Go down and the light runs out before anything else does. Then the warmth. Then the pressure keeps climbing the whole way with nothing to stop it. Almost every question a child has about the sea has the same answer, which is how deep. That is why there is a submarine in the story at all. A person cannot simply swim down, because the water stacked overhead pushes on everything under it, and past a certain point you need a hull rather than a breath.
The floor itself is the next thing, and it corrects a picture nearly every child is carrying. The ocean is not a bowl that gets deeper toward the middle. There is a shelf out from the coast that stays shallow for a long way, a slope down off the edge of it, wide flat plains at the bottom, and then mountains and trenches. It is a landscape. Draining it would leave terrain, not a basin.
The reef gets its beat, and the useful thing in it is that coral is an animal rather than a rock or a plant. The reef is the stone those animals leave behind them with a living skin on the outside. This book puts that on the page and moves on, which is fine, and if your child catches fire on it there is a whole graphic novel on our shelf that does nothing else.
And then the vents, which are the reason to own the book.
Everything a child has been taught about food starts with the sun. Sunlight makes plants, plants feed animals, animals feed other animals, and the chain always runs back to the same place. The book takes them somewhere with no sunlight at all, miles below anything green, and there is a crowd living around a crack in the sea floor where hot water comes out. Not a few stragglers. A community. What feeds it is chemistry coming up out of the ground rather than light coming down.
That single page does something no worksheet does, which is show a child that a rule they were taught is a rule and not a law of the universe. There are exceptions, the exceptions are real, somebody went and found this one, and the textbook version had to change afterward. A seven year old cannot say all of that. A seven year old can absolutely say that there are animals living in the dark that do not need the sun, and be a little bit outraged about it, and that outrage is the beginning of the whole thing.
The last piece is quieter and worth naming. Most of the deep is fed by what falls into it from the sunlit water far above. The dark is not separate from the surface. It is downstream of it.
The child it lands with
The child who has already worn out the shark books and wants what is under the sharks.
The child who has met photosynthesis, in a workbook or from you, and is at exactly the right moment to be handed the exception to it.
Not the child who is genuinely anxious about deep water. See below.
One place to stop and talk
The vent page is where to slow down, and the question that opens it is one your child can already answer wrongly with confidence: where does all food come from?
They will say the sun, because that is what they were taught and it is nearly always true. Then look at the picture together and let them work out what is eating what down there in the dark. The answer is that the hot water carries chemicals up out of the rock, and there are things living down there that can make food out of chemicals the way a plant makes food out of light.
It is worth adding one sentence about how this got known, because it is recent enough to be a story rather than a fact. People went down in a submersible looking at the sea floor and found the crowd around the vents, and nobody had expected it. Science books had to be rewritten. Being able to say that a book was wrong and then got fixed is a better thing for a child to carry than any particular animal's name.
What to know going in
The caution on this one is not a frightening page. It is a shallow one.
This book takes on more subjects than any other Magic School Bus title on our shelf, and each of them gets less room as a result. The sea floor, the reef, the animals, the plants and the vents all pass by in one trip. Compared with the human body book, which follows a single bite of food from one end to the other and does it properly, this is a tour rather than a route. That is not a reason to skip it. It is a reason to know what you are buying, which is a wide first pass with one genuinely excellent page in it, rather than a unit that will hold a curious child for a month.
Two smaller things. Deep sea animals look strange, and the book draws them, so a child who is unsettled by teeth in the dark will meet a few. Nothing in the story is presented as dangerous and the tone stays comic throughout, but the pictures are the pictures.
And the water itself. The class goes under the sea in a vehicle without a parent anywhere in sight. For most children that is the good part. For a child who is anxious about deep water or about being underwater specifically, this is not the gentle introduction it looks like from the cover, and the lifeguard chasing them the entire time is played for laughs rather than reassurance.
The store bands it 2 to 5. That band is about content, and the margin reports run dense for a second grader reading alone.
Where to get it
Own this one second. Start a child on the human body book, which is the best built of the series, and come back for this at $8.99 at The Magic School Bus on the Ocean Floor once photosynthesis has landed, because the vent page is worth four times what the book costs to a child who has just been told that everything alive is fed by the sun. If your child is already deep into reefs specifically, the Science Comics volume on coral reefs will serve them better than this will, and it costs more for a reason.
If your child liked this one
Books we have written about that sit close to this one, by reading level and by subject.
A Beehive Is a City: The Magic School Bus Inside One
The Magic School Bus Inside a Beehive by Joanna Cole
Grade 2 to 5
Magic School Bus Dinosaurs: The Feather Problem
The Magic School Bus in the Time of the Dinosaurs by Joanna Cole
Grade 2 to 5
Who Was Albert Einstein? The Science Behind the Hair
Who Was Albert Einstein? by Jess Brallier
Grade 2 to 5
Browse every book we have written about by age, by kind of book and by subject: Find the right book for your child. Or see the whole Stealth Science shelf.
