Readers enter the underwater world of extreme submarines with this text, which offers a high-interest take on the career, technology, and engineering curricula in elementary classrooms. Readers learn the basics of submarine technology and how submarine crews live inside the machine. The text examines the ways in which submarines are used, including civilian and military missions, and how they escape detection in the deepest depths of the oceans. Familiar submarines, such as the Deepsea Challenger and those used in the U.S. Navy, are examined in-depth. Colorful photographs bring extreme submarines to life, while fact boxes and sidebars offer opportunities for additional learning.