Flotsam & Jetsam

A Dancing Turtle? Have you witnessed a turtle revolving seemingly wildly in the water? Well, it's not so wild, say scientists at the University of North Carolina, who have published a ground-breaking study of how turtles navigate. Their instinctive dance aligns themselves with the Earth's magnetic field. The researchers conditioned captive loggerhead turtles to specific magnetic fields by replicating specific oceanic locations, repeatedly feeding the turtles in some places but not in others. When excited by a familiar magnetic signature, the turtles would lift their heads at the surface with mouths open, slap their flippers, and often spin in circles.

Jaws is 50: This summer, you can revisit Spielberg's ground-breaking movie. Jaws, as Universal plans a nationwide re-release of the film from August 29 through September 4, with plenty of new streaming opportunities. But see it in a theatre, where that deep bass -- da dum -- and the sharks in your face may still give you the willies. Afterward, go to social media and explain that it's a fantasy. You can dive up close with sharks, but shark finning must end.

What Happens in Sydney May Not Stay in Sydney. The MHAS Adelaide, a former warship sunk off Avoca Beach, Australia, in 2011 as an artificial reef, has been closed to divers because the effects of recent storms may make it dangerous to divers. Local dive operators are concerned because they are losing business. Could the effects of hurricanes mean a similar fate for Florida's many wrecks sunk as artificial reefs?

Great White Goes Tropical. Bali's Nusa Penida is well known for encounters with mola mola and manta rays, but a group of divers led by Swedish Fabian Clinton, from Scuba Junkie Penida, were surprised to encounter a great white shark while they were diving at 70 feet in mid-March. Dutch national Amber Doornekamp said: "The size of the shark was like nothing I'd ever seen before. It reminds you of how small people are." Fabian captured footage of the 20-second encounter on his GoPro and posted it on his Instagram page. You can see it here.

Snorkeling Boat Tragedy in Bali. A 39-year-old Australian woman was killed when a boat that had carried snorkelers to Nusa Penida capsized in turbulent seas on March 22. She was thrown into the sea when the Sea Dragon boat she was in was overwhelmed by a massive wave. The rest of her group of 11 were in the water at the time, and two crew joined them when a second wave capsized their vessel. A nearby boat rescued the 13 survivors, who were treated in a local health clinic. Maritime accidents have killed hundreds of people in Indonesia in recent years. (The Guardian)

Looking for a Reef-Safe Sunscreen. The best available is Thrive Bodyshield SPF 50, says Wirecutter, which has evaluated sunscreens for 11 years. The New York Times product testing column says it spreads quickly and absorbs easily for a sunscreen containing only physical UV blockers that reflect the sun's rays. "Its feel and appearance on all shades of skin is on par with most chemical sunscreens we've considered." It's compliant with the Hawaii 104 Reef Act, which bans sunscreens that affect coral.

Aussie Divers Rescued by a Ferry. Two Australian brothers diving with Perth Diving Academy, based at Hillary's Boat Harbour, were left at sea after their day boat returned to shore without them. Though they had no surface marker buoys, a crew member aboard a local ferry spotted them two miles off the coast several hours later. One climbed onto the ferry, while the tour operator's boat took the other back. Perth Diving Academy director Troy Lane refused to comment to the press, only saying everyone was safe and "Nobody died." Australian officials are investigating an incident, certainly motivated by that kind of nonchalance, and the two brothers have hired a lawyer (ABC News)

Lost to a Vortex? Emily Sherwin, a 20-year-old diver who went missing during a dive last year off the south coast of England was "caught in a "vortex," according to a Coroner's report delivered at the inquest into her disappearance. But, unless somebody pulled a plug, there was no "vortex." Like Cozumel, it might have been a down current caused by the topography. In the UK, at the edge of Europe's continental shelf, a down current could be easily enhanced with a strong tidal flow from the Atlantic that can move an object many miles. Tragically, her body has never been found.