Designed and built as the newest icListen software for hydrophone arrays, Lucy II, is a PC software program developed by Ocean Sonics. It detects, locates, and tracks sound sources. Tailored for using one or more hydrophones, Lucy II is the next step in acoustic processing software, enhancing the original capabilities of Lucy. Now, users can employ Lucy II to stream, record, and analyze an array of icListen hydrophone data. The program’s interface is crafted to present data graphically and numerically, optimizing usability for field operations teams, making it highly task-focused and user-friendly.