An other way to look at this whole commercial diver vs. scuba diver is the fact that people who train and work as commercial divers tend to be experienced people and that is what keeps them safe. The second key to this is the equipment. If you have someone in gear working that is safer than say scuba. This all comes at a cost. This cost will be more than your buddy and his scuba gear and that is the crux. Commercial companies can't compete with some guy and his scuba gear. That guy might know what he is doing or not, and because of this safety is an issue.