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.
You may also have the option to enroll in a Deep Diver Specialty course wherein you will be trained to dive as deep as 40 meters (140 feet). After your certification, you may plan to go deep diving with an experienced dive buddy. Some deep diving sites may take you to shipwrecks or may require you to use an enriched air to extend your dive time.