The oceans cover 71% of the Earth’s surface and represent one of the least explored frontiers; yet, the oceans are integral to climate regulation, nutrient production, oil retrieval, and transportation. Also, water systems in general are of vital importance to life on Earth and commerce. For these reasons, there is significant interest in monitoring aquatic environments for scientific, environmental, commercial, safety, and military purposes. WUWNet is the premier venue for research and development bringing real-time, in-situ sensing and actuation to this aquatic world. The goal of this conference is to bring together researchers and practitioners in areas relevant to underwater networks and systems. Thus, many aspects of the networking protocol stack - from the physical layer to the application layer and the various system issues - will be represented at this conference. The objective is to serve as a forum for presenting state-of-the-art research and development, for exchanging ideas and experiences, and for facilitating interactions and collaborations. The conference will span three days, including presentations of keynote speeches, plenary talks, technical papers, and posters/demos. The scope of the WUWNet conference covers a broad range of research directions relevant to underwater networks and network-related signal processing, communications, systems, and applications.