The oceans were once mysterious and dangerous places that humans didn't know much about. While the oceans still hold some secrets, thanks to innovative machines, people can explore and travel into their depths like never before. This motivating, high-interest book with a dynamic design introduces readers to incredible vehicles such as submersibles, icebreakers, cargo ships, and many more. Accessible text is supported by Fast Fact boxes, highlighting key information, and full-color photographs of each machine's inside and outside.