Individuals with disabilities are trained and certified using a multilevel certification system. This system is designed for training individuals with disabilities such as paraplegia, quadriplegia, visual impairments, high-functioning brain injuries, or mild intellectual disability. HSA bases its students' diving proficiency on their ability to assist another diver in the water. For instance, a Level A diver is certified to dive with one other person; a Level B diver must dive with two other able-bodied divers and a Level C diver also requires two dive buddies, but one must be trained in diver rescue. After meeting the requirements for basic "open water," some A, B and C divers can go on to obtain an advanced level of certification.