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.

Dubbed Jiffy Lube2 by researchers, the 63-kilogram mako is making waves amongst scientists studying sharks. The shark swam 17,700 kilometres using a route that researchers at Nova Southeastern University had never seen before: looping the Atlantic twice, venturing north far north to Nova Scotia south to the Bahamas. “This is the only shark that’s made this double southerly migration,” said Mahmood Shivji, director NSU’s Guy Harvey Research Institute, which has tracked a total of 130 sharks since 2008.