The Super Sub from above being tested off the island of Curaçao will soon be delivered to its new owner (Picture: Tom van Oossanen/U-Boat Worx/Cover Media)

Meet the Super Sub,a sleek submarine been dubbed the underwater supercar.

The $5.75m (£4.3m) craft is the world’s fastest submersible with a top speed of nine knots (10mph),as fast as a cruising dolphin.

It can carry three people to a depth of 300 metres and will soon be ready for action on a billionaire’s yacht after completing sea trials.

The interior of the craft (Picture: Tom van Oossanen/U-Boat Worx/Cover Media)

Manufacturer U-Boat Worx put the vessel through its paces in an intensive testing programme off Curaçao,an island situated north of Venezuela.

Engineers assessed performance,safety systems and handling and declared it ready for action.

The Super Sub can ascend and descend at angles of up to 45 degrees,enabling it to navigate complex underwater terrain with what the company says is greater control and manoeuvrability than traditional submersibles.

With an operational depth of 300 metres and a range of up to ten nautical miles,it is designed to combine speed with extended exploration capability.

The submersible has been compared to an underwater supercar and comes with a host of features (Picture: Tom van Oossanen/U-Boat Worx/Cover Media)

Engineers said the trials focused on validating propulsion systems,avionics-style controls and onboard safety features.

These included a sonar system that continuously scans the seabed and automatically adjusts the craft’s trajectory,as well as redundant life-support and control systems.

The company says the submersible has been designed to offer a ‘flight-like’ experience underwater,using hydrodynamic lift to create a smooth forward motion during descent.

The Super Sub just below the surface of the water. It can dive to 300 metres (Picture: Tom van Oossanen/U-Boat Worx/Cover Media)

The submarine is equipped with a powerful light for surveying the underwater world (Picture: Tom van Oossanen/U-Boat Worx/Cover Media)

It is also fully equipped with safety features including 96 hours of life support,a safety buoy and Maximum Depth Protection,an automated system which stops it doing too deep.

Images from the trials show the craft moving through open water with a winged profile intended to enhance stability.

Inside,a transparent acrylic pressure hull provides panoramic views,with seating arranged to maximise visibility for pilot and passengers.

U-Boat Worx,founded in 2005,said the Super Sub is intended for integration into luxury yacht programmes or as a standalone exploration platform.

A billionaire owner has bought the vessel (Picture: Tom van Oossanen/U-Boat Worx/Cover Media)

Its speed,the company added,could allow users to survey larger areas within a single dive,while maintaining the precision needed to inspect reefs,underwater cliffs and wreck sites.

The firm say final preparations for a handover to its first owner are now underway – with delivery due within weeks.