Underwater communication is much harder than over-the-air communication. Radio waves do not travel well in water. Underwater systems usually rely on acoustic communication, which uses sound to carry information. However, sound travels much more slowly and can transmit far less information than radio waves, making it difficult for underwater robots, sensors, and vehicles to communicate effectively and reliably. This project studies a new technique called underwater acoustic reconfigurable intelligent surfaces (UA-RIS). These are special panels that can control how sound waves reflect in water, helping signals travel farther and improving the amount of information they can carry. The goal is to build the scientific foundation for smart underwater communication and sensing systems that could support ocean research, environmental monitoring, offshore infrastructure inspection, and maritime security. The project also benefits society by training students, creating open tools and datasets for researchers, and engaging the public through education and outreach activities that encourage interest in ocean technology and engineering. This project aims to develop the theoretical, algorithmic, and experimental foundation of UA-RIS-assisted underwater networks through three tightly integrated research thrusts. First, it designs and models innovative UA-RIS architectures using coupled electromechanical and acoustic methods, including reflector analysis, propagation modeling, and communi