A CK-MB test may be used as a follow-up test to an elevated CK in order to determine whether the increase is due to heart damage or skeletal muscle damage.
Scuba organizations say recreational divers shouldn't go below about 130 feet, but one Egyptian diver recently ventured a bit deeper -- going more than 1,000 feet below the ocean surface and setting a world record in the process.
Most likely dolphins do not dive very deep though. Many bottlenose dolphins live in fairly shallow water. In the Sarasota Bay area, the dolphins spend a considerable time in waters that are less than 2 meters (7 feet) deep. Other whale and dolphin species are able to dive to much greater depths even.