Space is often referred to as the "final frontier," but in truth, humans know less about what lives in our oceans than we do about the far reaches of space. High pressure and low light make it dangerous for humans to explore the depths of the seas, which is why oceanographers have turned to robots in recent years. Vivid photographs, accessible text, and fact boxes give readers a glimpse into the world of ocean robotics, and engaging sidebars describe what we've learned from these amazing tools. A list of questions provides a starting point for more in-depth thinking about STEM.