Is it a huge whale lurking or an optical illusion?

The photograph was captured on Kailua Bay in Hawaii


At first glance, this dark shape lurking under the waves in the crystal waters off Hawaii looks like a massive predator.

The ' whale ' has been captured in a stunning photograph in Kailua Bay on the island of Oahu.

See also: 35ft humpback whale trapped in California harbour

See also: Enormous creature that washed up on an Indonesian beach identified

But if you look closer, the 'whale' shape is actually just an illusion.

In fact, amazingly it's a huge group of fish swimming together for social reasons, known as a 'shoal'.

Credits: © robertharding/REX/Shutterstoc

A group of fish swimming together

The little fish are said to be 'schooling' together - the term used to describe a group of fish swimming in the same direction.

They are creating the image of a much larger creature.

For scale, the motorboat on the left of the photograph is 12ft long, giving an idea of the size of the massive shoal.

Britain's amazing sea life

Britain's amazing sea life

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