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.
With our recreational diving limit of 130 feet we are hardly on our way to the deepest ocean bottom. Between the two extremes of how deep we can dive and the maximum depth, there are some interesting answers to the question of how deep is deep.