However, commercial divers trained in underwater welding are some of the most well-trained technical divers on Earth, and the career can be quite lucrative. This type of repair work often involves underwater welding, which is considered one of the most dangerous professions in the world. According to the U.S. Bureau of Labor Statistics, there were 3,380 commercial divers in the United States as of 2017. The commercial diving program at the Atlantic Commercial Diving Centre runs one course per year, and takes a maximum of 16 students. “You can let your mind run wild, there are multiple things that can hurt you in the water,” Johnston says.