Project Proposed: This project proposes a novel instrument and testbed environment based on a MIMO (Multiple-Input Multiple-Output) networking testbed for underwater deployment. The proposed instrument is based on a commercial system, i.e., Teledyne Bethos Telesonar modem, which would be extended for reconfigurability and rapid deployment, and thus adopted for wider usage. The basic extension of the existing commercial modem is the addition of an external controller hosting an open-source software communication suite. This software suite would provide the functionalities for reconfiguration of various networking functions for underwater deployment. The proposed instrument is expected to enable research in (i) underwater networking, (ii) acoustic signal processing and communications, and (iii) environmental ecosystem monitoring, modeling, and engineering, including: - MIMO underwater acoustic transceiver designs via high-end Digital Signal Processor (DSP) and a data recorder (hosted on the modems) for testing MIMO functions. - New MAC and routing protocols for underwater MIMO links and their testing under realistic conditions; - Collection of useful data that can be used in analysis and validation of theoretical models; - Access interface in order to allow other researchers to access the hardware; - Applications in a variety of important water and sea floor observation challenges, including earthquake and tsunami prediction, early warning and observation applications, as well as long term observations on water quality, currents, etc. in the Great Lakes. Broader Impacts: This project, unique in its goals and expected results, will provide the research community with an experimental platform for testing underwater communication ideas. The testbed will benefit research on underwater networking, acoustic underwater communications, and environmental monitoring. The developed testbed will be a research and training facility for undergraduate and graduate students, with unique theoretical and system design skills in underwater signal processing, communications, and networking. The PI and Co-PIs have a strong history and a current demonstration of their ability to attract and train both women and minorities in their areas of research. Students, including minority and women, will be engaged and a new course will be developed.