Committee on Seafloor Observatories: Challenges and Opportunities & National Research Council 
Illuminating the Hidden Planet [PDF ebook] 
The Future of Seafloor Observatory Science

Despite our reliance on the ocean and its resources, it remains a frontier for scientific exploration and discovery. Seafloor observatoriesunmanned systems of instruments, sensors, and command moduleswill have power and communication capabilities to provide support for spatially distributed sensing systems and mobile platforms. Illuminating the Hidden Planet is a voyage to the bottom of the sea, advancing oceanographic science further through long time-series measurements, to discover the mysteries of the deep that have, until now, avoided scientific opportunity.