handout artists' impression of one of the bedrooms in a typical configuration of DEEP's Sentinel System. Each room enjoys the view through a huge viewport overhead, and lots of space for personal items and storage. A touchscreen device may be used for communications and entertainment. A new deep-sea habitat project has been launched by ocean technology and exploration company, DEEP, which has announced its intention to create a permanent human presence under the oceans by 2027. The project is already two years in development, with its base located at the former British National Diving and Activity Centre (NDAC), an 80m-deep, 600m-long flooded quarry in Gloucester, England, which suddenly announced its closure in February 2022. The centrepiece of DEEP’s project is Sentinel, a customisable capsule system designed to be ‘modular, scalable, autonomous, recoverable, re-configurable and re-deployable.’ Sentinel can be tailored to the individual needs of its users, be that a single installation or a network of segments interlinked to form a ‘deep-sea village’, and DEEP claims it will be installed on the sea floor with minimum disturbance to the surrounding ecosystem. Built using an innovative construction method employing robotic welding arms, which will deposit high grade steel using wire arc additive manufacturing, essentially a form of 3D-printing but with metal, the Sentinel system will be extremely resilient to pressure, and will be built with several degrees of redundancy in case of failure. The modules will be deployable at depths of up to 200m, which will allow it to be explored on much of the global continental shelves, with its residents having unfettered access to the epipelagic, or ‘sunlight’, zone of the ocean, where it is estimated that 90 per cent of all ocean life resides. The pods will be constructed to be comfortable living spaces as well as scientific research stations. Each of the modules 6m in diameter, approximately the same width as the fuselage of a Boeing 777, and capable of catering to a crew of 6. As living on the station involves full-saturation diving, crewmembers will rotate on a 28-day cycle, with around 20 spent onboard, depending on the depth and decompression profile of the deployment.ach component allows for the system to be extended. Photo by DEEP via ABACAPRESS.COM