The National Science Foundation's (NSF) Ocean Observatories Initiative (OOI) [http://oceanobservatories.org/infrastructure/ooi-station-map/regional-scale-nodes/ Regional Scale Nodes] (RSN) component is an electro-optically cabled underwater observatory that directly connects to the global Internet.  It is the largest cable-linked seabed observatory in the world, and also the first of its kind in the United States.
Located on the southern part of the Juan de Fuca plate, off the coast of Washington and Oregon, it is the first ocean observatory to span a tectonic plate.
RSN utilizes several high-power, high-bandwidth sub-sea terminals called primary nodes which are linked together by fiber-optic cable and provide support to oceanographic sensors at key [http://www.interactiveoceans.washington.edu/story/V14_Science locations].
Upon completion of the network in 2014, RSN will cover a distance of over 900 kilometers at depths of up to 3000 meters.  Implementation of the OOI Regional Scale Nodes is led by the University of Washington's (UW) [http://www.ocean.washington.edu School of Oceanography], the [http://www.apl.washington.edu UW Applied Physics Laboratory], and [http://www.l-3mps.com/maripro/index.aspx L-3 MariPro].
Live RSN data from >100 seafloor and water column instruments will be made available live on the Internet.  This will allow both scientists and the general public to study long-term changes in ocean systems over the next 25 years.
Construction of RSN will be completed in 2014.  Efforts are substantially aided by the crews of [http://www.ropos.com/ ROPOS (Remotely Operated Platform for Observation Sciences].  The [http://www.interactiveoceans.washington.edu/story/VISIONS_14 83-day VISIONS ’14 expedition] aboard the 274-foot global-class R/V Thomas G. Thompson is responsible for the observatory's final implementation.