Developed by roboticists from Queensland University of Technology, this is the world's first robot designed to search and destroy (so to speak) the dreaded crown-of-thorns starfish (COTS). It does this by seeking them out, identifying them and then administering a lethal injection of bile salts.

Its creators, Dr Matthew Dunbabin and Dr Feras Dayoub, equipped the robot with GPS, stereoscopic cameras for depth perception, thrusters to improve stability, pitch-and-roll sensors as well as the pneumatic injection arm.

Back when intrepid men donned hard hats to plumb the depths, they didn’t leave the surface without a trusty sheath knife. Wood-handled beauties like the brass-encased Morse MK V are works of art, and they make a great collectors item. But I can’t imagine any reason why I’d take one underwater.

Near sanctuary zones at Mangrove Bay and Coral Bay, marine biologists tagged 83 reef sharks. They then tracked the sharks' movements in order to find out how much protection the marine park provides the sharks. Over a two-year period, the movements of blacktip reef sharks, grey reef sharks and sicklefin lemon sharks at Ningaloo Reef were examined.

SS Central America, known as the Ship of Gold, was a 280-foot (85 m) sidewheel steamer which sank in a hurricane off the coast of the Carolinas in September 1857, along with more than 420 passengers and crew and 14 tonnes of gold with an estimated value of $300 million on today's market.

With so much money on the line, ownership of the loot has been entrenched in legal battles ever since its discovery by Columbus-America Discovery Group in 1989.