Never take a system from an air-conditioned environment directly into the sun. Allow the system to warm up slowly so that condensation will not form inside the viewfinder and lenses. Never leave the camera system exposed to direct sunlight. Excessive heat can melt glues and warp plastic parts. Never jump into the water with a camera system in your hands.
Sudden impact can jar a lens or fitting loose and break the watertight seal.
Have someone hand it down to you. Never use a system that does not pass all pre-dive checks. If you have any doubts about the watertight integrity of the system, bring it to an authorized repair facility for examination. Before using your equipment, carefully inspect all the O-rings for salt, dust, sand, hair, cracks, nicks and any debris or damage. If an O-ring is dirty, clean it.