Book excerpt: Automated insulin delivery is a new type of technology that uses an algorithm (a set of rules) based on continuous glucose monitor data and insulin pump data to decide whether an insulin pump should give more or less insulin. This book explains the basics of scuba diving and uses it as an analogy for how an automated insulin delivery system makes small changes to manage blood glucose levels, similar to how a scuba diver makes small changes to manage their balance (called buoyancy) in the water. This book can be used to help explain diabetes technology to kids, their friends and schoolmates, and even your family members to help them understand how this technology helps make living with diabetes easier.