Shark proof cage
Encyclopedia
A shark proof cage is an extremely strong metal cage
used by a SCUBA diver
to safely examine dangerous types of shark
s up close, such as the Great White shark
or bull shark
. Shark proof cages are built to withstand being rammed by large, powerful sharks. The cages provide a visual and tactile deterrent to sharks. Cage diving allows people to come very close to sharks and is mainly used for Great White sharks.
On September 4, 1979, US patent
number 4166462 was issued for a self-propelled shark proof cage ; the cage was designed to allow abalone
divers to collect abalone without becoming vulnerable to attack. Thanks to the propulsion system, the abalone divers would exert themselves less and therefore be able to collect their prey for longer periods of time. The patent abstract
details a self-propelled cage with at least one access opening and a propeller mounting frame that carries both an air motor and a propeller. Buoyant objects are attached to the frame so that the cage may be made approximately the same density as saltwater
. This patent expired on September 4, 1996.
In 2007, due to poor shark wrangling a commercial shark cage was destroyed off the coast of Guadalupe Island
after a 15-foot Great White shark
became entangled in it and tore the cage apart in a frantic effort to free itself. Tourists captured video of the incident, which quickly spread throughout the Internet
.
Cage (enclosure)
A cage is an enclosure made of mesh, bars or wires, used to confine, contain or protect something or someone. A cage can serve many purposes, including keeping an animal in captivity, capturing, and being used for display of an animal at a zoo.-History:...
used by a SCUBA diver
Scuba diving
Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater....
to safely examine dangerous types of shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
s up close, such as the Great White shark
Great white shark
The great white shark, scientific name Carcharodon carcharias, also known as the great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. It is known for its size, with the largest individuals known to have approached...
or bull shark
Bull shark
The bull shark, Carcharhinus leucas, also known as Zambezi shark or unofficially known as Zambi in Africa and Nicaragua shark in Nicaragua, is a shark common worldwide in warm, shallow waters along coasts and in rivers...
. Shark proof cages are built to withstand being rammed by large, powerful sharks. The cages provide a visual and tactile deterrent to sharks. Cage diving allows people to come very close to sharks and is mainly used for Great White sharks.
On September 4, 1979, US patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
number 4166462 was issued for a self-propelled shark proof cage ; the cage was designed to allow abalone
Abalone
Abalone , from aulón, are small to very large-sized edible sea snails, marine gastropod molluscs in the family Haliotidae and the genus Haliotis...
divers to collect abalone without becoming vulnerable to attack. Thanks to the propulsion system, the abalone divers would exert themselves less and therefore be able to collect their prey for longer periods of time. The patent abstract
Abstract (summary)
An abstract is a brief summary of a research article, thesis, review, conference proceeding or any in-depth analysis of a particular subject or discipline, and is often used to help the reader quickly ascertain the paper's purpose. When used, an abstract always appears at the beginning of a...
details a self-propelled cage with at least one access opening and a propeller mounting frame that carries both an air motor and a propeller. Buoyant objects are attached to the frame so that the cage may be made approximately the same density as saltwater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...
. This patent expired on September 4, 1996.
In 2007, due to poor shark wrangling a commercial shark cage was destroyed off the coast of Guadalupe Island
Guadalupe Island
Guadalupe Island, or Isla Guadalupe is a volcanic island located 241 kilometers off the west coast of Mexico's Baja California peninsula and some 400 kilometers southwest of the city of Ensenada in Baja California state, in the Pacific Ocean...
after a 15-foot Great White shark
Great white shark
The great white shark, scientific name Carcharodon carcharias, also known as the great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. It is known for its size, with the largest individuals known to have approached...
became entangled in it and tore the cage apart in a frantic effort to free itself. Tourists captured video of the incident, which quickly spread throughout the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
.