A desperate search is underway for the missing Titanic submersible which has vanished 12,500ft below the Atlantic Ocean.
Efforts continue to find them before their oxygen runs out, the watercraft is thought to have under 70 hours of air left.
If they can be found, the operation would be 11,000ft deeper than the deepest successful undersea rescue in history.
But what exactly is a submersible? Read on to find out what the underwater vessel is and what it is used for.
A submersible is a type of watercraft designed to operate underwater being fully submerged.
Many people colloquially refer to a submersible as a submarine, yet a submarine is an independent cruiser with its own power supply and air renewal system.
A submersible, however, needs to be supported by a nearby surface vessel or shore team.
Some operate on a ‘lether’ or ‘umbilical’ while connected to the surface vessels.
They have been used worldwide to assist oceanography, underwater archeology, ocean exploration, equipment maintenance, recovery and underwater videography.
Submersibles have been able to reach over 10 km below the surface of the water.
What are submersibles used for?
In their early days, submersibles were used in war, American inventor David Bushnell in 1775 used them as a means to attach explosive to enemy ships during the American Revolutionary war.
The device, dubbed Bushnell’s Turtle, was oval-shaped and made from wood and brass.
In recent years, private firms such as OceanGate, Sportshub and Triton Submarines LLC, have created small submersibles for tourism, exploration and adventure travel.
Prior to that, the submersible was a technology designed for research and exploration purposes, including search for shipwrecks and to document underwater activity.
Some submersibles have been known to venture great depths of the Ocean, in 1960 The Bathyscape Trieste made history and was the first to reach the deepest part of the ocean, reaching nearly 11km at the bottom of the Mariana Trench.
Since then Titanic film director James Cameron reached the deepest-known point on Earth in 2012.
In the Bathyscape named Deepsea Challenger, Cameron reached the deepest part of the Mariana Trench in record breaking time after just two hours and 36 minutes of descent from the surface.
The solo-diver recorded reaching 35,787 ft on the fourth ever dive of the Challenger Deep.
How many types of Submersibles are there?
There are many types of submersibles which can include a crew or venture into the ocean alone, otherwise known as remotely operated vehicles or unmanned underwater vehicles.
Manned submersibles generally only hold capacity for a limited crew between one to four people, these are usually great for research and exploration.
Unmanned submersibles are used for research or commercial purposes, such as pipeline or oil rig work.
Some submersibles may be small and hold a small crew and no living facilities.
Each type of submersible utilises the same major types of technology, such as buoyancy control, and ‘wet subs’ which offers underwater breathing equipment for a crew if the waterfloods the interior.
Another technology called ambient pressure maintains the same pressure both inside and outside the vessel.
In addition, single atmosphere submersibles have a pressure hull with internal pressure maintained at surface atmospheric pressure.
