You should probably never try this when you go scuba diving but watch this scuba diver turned shark whisperer instantly immobilize a shark and put it to sleep with a touch of the nose. The diver uses a technique called tonic immobility, he basically holds the sweet spot on the shark's nose to put it in a trance.
DISCUSSION
When I helped my son with a shark report I learned that a shark cannot stop moving or it will drown.