The global importance and impacts of the ocean motivate diverse investigators and connect many nations in the need to better observe and understand the ocean. A vast reservoir of potential discovery, as well as a central driver of our climate system, the global ocean has major impacts on human society. Ocean exploration will provide many images of stunning beauty and new insights and knowledge. At the same time, there is increasing awareness that the ocean-atmosphere modes of variability over seasonal to decadal time-scales -- including the Indian monsoon, El Nino Southern Oscillation, Pacific Decadal Oscillation, and North Atlantic Oscillation -- as well as triggers in the deep ocean of destructive hazards affect large populations. Benefits are being derived from newly discovered marine organisms, even while the marine ecosystem is challenged by warming and acidification. New tools for exploration and investigation, including sites for sustained observations and the means for serving ocean data to increasingly diverse users, are being put in place. These tools are complemented by private sector investments in eco-genomics, robotics, digital imaging, high-speed communications, cloud-computing, power extraction from the ocean, and nanotechnology. Together, these will enable new studies of the data-sparse ocean, better investigation of the societal impacts of ocean variability and change, and development of applications of ocean data and understanding that address the needs of society.