Asphyxiations, strangulations, suffocations

A dive team was attempting to investigate a target of interest near a buoy. After all pre-dive checks, the diver was given clearance to descend. He followed the marker buoy line to the bottom. When he arrived at the bottom, he lost the marker line and ascended back to the surface. Once he found the proper marker, he descended again to the bottom. He was not able to breathe with his breathing apparatus and lost communication with the dive master. When he was pulled to the surface, he was not breathing and required hospitalization.