This book was written to document and share our updated knowledge of airborne lidar hydrography gained since Gary C. Guenther wrote the original seminal book Airborne Laser Hydrography - System Design and Performance Factors over 30 years ago. Like the first book, commonly referred to as the Blue Book, this Blue Book II updates the history, theory, and design challenges of bathymetric lidar. However, with over 30 years of advancements and most importantly with thousands of hours of operational experience from different international teams and system, Blue Book II provides knowledge gained through decades of operational experience over a wide range of applications and environmental conditions. Mr. Guenther’s Blue Book laid the foundation that over 16 authors from a half dozen countries update in Blue Book II.