Abstract: The present invention provides the swimmer and or diver with protection against a shark. A probe held by the user can be deliberately armed before use. When armed the probe has protruding from its front end a dart. The dart is provided with a trigger restrained from operating by a trigger washer. When the dart is plunged into the shark's body it penetrates the skin and enters the body. The trigger washer no longer restrains the trigger which then allows a gas from a cartridge to enter the shark's body cavity. The gas bloats the shark's body causing the shark to rise in the water having lost the ability to maneuver.