This common mining method starts from the earth's surface, maintaining exposure to the surface throughout the extraction period. Open-pit mining is practical when the ore-bodies of the rock are large and located closer to the surface. An advantage of this method is that mining equipment will not be restricted by the size of the opening you are working in.
Underground mining is used to extract ore from below the surface of the earth safely. Tunnels known as shafts are built to allow for entry into the underground mines through the surface. This method is practical when underground mining has a lower ground footprint than open-pit mining.
Underwater mining is the best option when the product you’ve identified is located within an environment like the seafloor. The sea has its local ecosystem therefore your mining approach has to be well thought out before any digging begins.