Atlantic Ocean Tunnel Atlantic Ocean Tunnel The Atlantic Ocean Tunnel () is an undersea tunnel that is part of Norwegian County Road 64 which connects Kristiansund Municipality to Averøy Municipality in Møre og Romsdal county, Norway. The eastern end of the tunnel is on Kirkelandet island in the town of Kristiansund and the western end of the tunnel is on the island of Averøya, just west of the village of Sveggen. The long tunnel runs beneath the Bremsnesfjorden, reaching a depth of , making it one of the deepest undersea tunnels in the world. Construction began in 2006, and the tunnel opened on
Challenger Deep multibeam echosounder technologies a depth uncertainty of ± (95% confidence level) on 9 degrees of freedom and a positional uncertainty of ± (2drms) remain and the location of the deepest depth recorded in the 2010 mapping conducted by the US Center for Coastal & Ocean Mapping/Joint Hydrographic Center (CCOM/JHC) aboard is at (). In November 2016 sonar mapping of the Challenger Deep area was conducted by the Royal Netherlands Institute for Sea Research (NIOZ)/GEOMAR Helmholtz Centre for Ocean Research Kiel aboard RV "Sonne". Using a Kongsberg Maritime EM 122 multibeam echosounder system coupled to positioning equipment that can determine latitude