A marine welder is responsible for diving underwater to perform welding on offshore equipment. They work in various water environments while performing their craft for commercial customers. These skilled craftsmen are usually certified by the American Welding Society and other professional organizations. As certified divers, they are capable of performing hyperbaric welding at a variety of depths. As highly qualified welders, they can handle precision work under potentially dangerous conditions. Marine welders can be called on to perform initial construction work as well as follow-up maintenance duties.