Longreach shoots an emergency buoyancy aid 500 feet out to sea. It is made from hydrophobic foam which rapidly expands upon hitting the water.
It is equipped with flares for night-time illumination and allows the victim to remain buoyant for a longer period of time.
The winner Australian Samuel Adeloju was chosen from a final international shortlist of 15 by inventor James Dyson.
Australian Samuel Adeloju with his prize-winning invention
James Dyson said: 'Longreach is a smart solution to a very real problem. A product’s functionality couldn’t be more important when it’s used to save someone’s life.'
Each year around 100 people drown off the UK coast and more than 13,500 incidents occur due to swimmers been swept out by rip rides or currents.
Mr Adeloju, 24, an industrial design graduate from Sydney, will receive a £10,000 cash prize. His engineering faculty at the University of New South Wales will also receive £10,000.
Mr Adeloju will also have the chance to visit Dyson’s research, design and development centre and learn more about its design process engineers there .
The inspiration for Longreach came from a military training session during Samuel’s army reserve training, where weapons that propel grenades and flares were demonstrated.
Samuel said: 'After learning about propulsion technology in grenade launchers, I had to find a chemical that would expand to forty times its size in just fifteen seconds upon hitting water.
‘After four months of testing I found that hydrophobic foam worked and soon after the concept for Longreach was developed. Winning the James Dyson Award will give me the financial support to develop a prototype and carry on testing'.
Samuel is already in talks with the Surf Life Saving Australia and Westpac Rescue – an aeromedical search and rescue service - to mass produce his invention.
The runners-up were the Seakettle, which uses natural sunlight to desalinate water in the emergency life raft and the Reax, an invention to help paramedics compress a patient’s chest at regular intervals.
There are a number of entries from the UK that include an electrostatic notice board, which suspends paper and objects without the need for pins. The user simply rubs the object against the board to produce an electrostatic charge.
Another UK entry was a water bottle that uses ultraviolet light to sterilise drinking water anywhere in the world.
Other inventions among the finalists included Flow2, a mask that holds an oxygen tube to a patient's head, and Reanimation, a resuscitation vest that pushes blood into the brain better than a manual cardiac massage.
Others include a sports bag that neutralises odours and a battery that helps cyclists get uphill.
