Installation of the 900 km (540 miles) of the main, or backbone, OOI cable off the coast of Oregon was completed on September 5, 2011. Of that total, 300 km (180 miles) was buried out to 1 km seaward of the water depth of 700 fathoms in order allow continued fishing in those areas. Remotely operated vehicles were used to conduct post-lay inspections and any needed remedial burial.The remaining 600 km (360 miles) of cable were laid in deep waters without the need of burial.
The installation team was made up of individuals from L3 MariPro, the contractor for the design and build of the cabled Primary Infrastructure; TE Subcom, L3 MariPro's subcontractor for cable installation; the Oregon Fishermen’s Cable Committee; National Marine Fisheries Service Protected Species Visual Observers program; OOI Regional Scale Nodes Marine Operations; and the Consortium for Ocean Leadership.
Originally scheduled as a two-month operation that began on June 28, 2011, a short and break occurred in late August for a vessel and ROV switch in Portland, Oregon: The ROV carried on the cable ship TE SubCom Dependable needed repairs and the installation team returned to finish the job within a few days on the TE SubCom Sentinel with a different ROV.
Cable inspection was also undertaken as part of the VISIONS '11 research expedition using ROV ROPOS deployed from the University of Washington's R/V Thomas G. Thompson. Some suspended lengths of cable were discovered around Axial Seamount and other lengths were found to have been laid through areas of active hydrothermal venting. Remedial measures are being discussed and planned.