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.
The final step toward becoming a certified scuba diver is to complete four open water training dives under the supervision of an instructor. These dives are conducted in a large body of water like the ocean or a lake to depths between 15 and 60 feet over two or more days.