>> this great white shark about four meters ten grabbed me and i was underneath the water looking at the shark face to face. >> despite his rendezvous with death, shannon still surfs. a rubber glove protects his fragile hand, a constant reminder of how fierce and fast these ocean creatures can be. >> quite scared to go out there. i just feel very lucky to be alive right now. >> elbow reef, key largo, florida. a nurse shark gets cozy with a diver and sends him to the hospital. >> instantaneously it hurt. it was almost like a firecracker going off in my mouth. >> for more than a decade, diver dave marcel has been leading scuba tours for curious thrill seekers. >> working with wild animals in