37 Installation, maintenance, building being installation, machinery retrofit and conversion, comprehensive preventive maintenance and repair of machines and equipment, transportable buildings of metal, metal building materials and equipment for dredging works, mining works, earthmoving works, offshore drilling works, soil treatment works and soil movement, particularly for marine and industrial applications; Installation, maintenance, building, machinery retrofit and conversion, comprehensive preventive maintenance and repair of dredging, mining and offshore vessels, structures of metal, offshore platforms, metal pipelines, particularly for marine and industrial applications; installation, maintenance, building being installation, machinery retrofit and conversion of drilling units, hydraulic rock breakers, remotely operated machines for underwater mining and dredging, treatment plants for the dredging, mining and offshore industry and lift systems for dredging, mining and offshore drilling operations; installation, maintenance, building being installation, renovation, life-cycle support being preventative maintenance and repair of machines, machine tools for dredging, excavating and offshore work, and for treating and moving dredged material, and deep-sea sampling tools for penetrating the seabed; installation, maintenance, building being installation, machinery retrofit and convention, comprehensive preventive maintenance and repair of nautical apparatus and instruments, surveying equipment, underwater sensors, depth finders for shipping, electronic and computerized installations for the manual and automatic regulation and control of dredging, mining and offshore vessels and dredging, mining and offshore apparatus and instruments; consultancy services relating to the aforesaid; dredging services; mining extraction services; offshore drilling services being the drilling of wells; on-site supervision of constructional works; machinery installation; mining extraction services including the extraction of oil and gas; repair and maintenance of dredging, mining and offshore vessels, machines and apparatus