 Divers carry a qualification record or certification card which may be required to prove their qualifications when booking a dive trip, hiring scuba equipment, filling diving cylinders or in the case of professional divers, seeking employment.Although recreational certifications are issued by numerous different diver training agencies, the entry-level grade is not always equivalent.Different agencies will have different entry-level requirements as well as different higher-level grades, but all are claimed to allow a diver to develop their skills and knowledge in achievable steps.