An intensive study to systematically observe sharks was launched by la France Porcher, a self-taught wildlife artist who published ethologist and the author of ‘The Shark Sessions’.

Porcher studied sharks without killing them and has documented their intelligence in the wild. She published an article to Live Science's Expert Voices: Op-Ed & Insights, which highlights that sharks are smart and curious.

These creatures sense their prey in the water but use a variety of tactics to remain hidden. Sharks use many tactics to avoid being seen. Sharks are so self-aware that if the spot prey in water, it comes only briefly into view at the limit of the visual range (the distance at which a view is obscured, from both you and the shark, by particles in the water). They are very alert to the moments and act while remaining hidden.

After a few minutes, this predator circles back assuming it’s still interested. Then they pass nearer and approach more directly to swim close by the prey or to sharply turn away.

There are many factors that influence the shark's approach. These include how curious and shy the shark is.

Porcher explained that during her ethological study of reef sharks in French Polynesia, young males appeared after sunset in excited bands to mate. They made no stealthy passes and just zoomed straight up to her.

But the older females, the biggest and shiest of the sharks would often linger out of visual range for long periods. They only made one or two cautious passes into view without ever coming near. The sharks that Porcher interacted with were vigilant and highly sensitive to attention and eye-gaze. Other ethologists have documented the same phenomenon occurring with terrestrial animals.