There are a lot of theories about what sharks are and aren't attracted to, with humans always trying to figure out what they should and shouldn't have in the water to stay safe from attack.
But the answers around whether or not sharks are attracted to light are murky.
This debate is renewed in "The Meg," this summer's shark movie that disturbs a prehistoric shark with bright submarine lights. Throughout the film, light is used both to attract sharks toward unsuspecting people and also to direct sharks away from others by distracting them with lights.
How realistic is the sharks' affinity for light?
Well, it depends on the kind of light. For example, "Mythbusters" tested how sharks respond to flashlights. First, they swam without any light at night and attracted six sharks. Then, they pulled out the flashlights and attracted so many sharks that they had to get out of the water.
The team concluded that the sharks' keen sense of electricity (which helps them hunt) also picks up on the electric pulses of the flashlights.
Another reason light could attract sharks has to do with how its prey responds to light. According to Discovery, light from ships can illuminate feeding zooplankton, which brings out the whole food chain from zooplankton on up to sharks.
It becomes a feeding frenzy.
Nature reported that fishing boats actually use big lamps specifically for this purpose because it draws their catch out of the deep and to the surface.
Florida Museum also cautions swimmers to avoid wearing jewelry that can glint in the water and look like fish scales.
Still, there are also scientists who say that light can help repel sharks.
Dr. Nathan Hart has studied shark eyesight and behavior extensively. He's the one who discovered that sharks are colorblind and therefore can only distinguish contrast, not color.
As Azula previously reported, that finding was key to his role in developing wetsuits and surfboard stickers that are striped to break up the person's silhouette.
The lines make it look less like a tasty seal from below.
Now he's testing lights to see if they can do the same thing.
According to The Australian, Hart attached "a system" of LED lights to the underside of a surfboard. Early tests found it to have a 100 percent success rate at confusing and deterring sharks from attacking.
Hart believes this works because it breaks up the outline of the board and the shark can't figure out if it's prey or not, so it leaves it alone.
But before you go strapping your own lights to yourself and your surfboard, Hart cautions that the pattern and brightness of the lights makes all the difference.