There are several HSE qualifications, each focusing on a different type of equipment or type of diving activity, for instance the HSE Scuba qualification only recognises the holder's competence to dive using scuba equipment. Training usually takes place at a residential school, with courses taking anything between 9 and 13 weeks although divers with existing qualifications, such as former military divers can take courses which build on their existing knowledge and experience. During training, divers will be taught how to use common types of diving equipment (nearly every school trains divers to use the Kirby Morgan equipment) and how to carry out underwater construction techniques such as welding and cutting.