It was a warm summer night on Otres beach, Sihanoukville, Cambodia in February this year when my friend Tea, two travellers from Italy and India and I decided to take a night swim after dancing and drinking in a local bar. We plunged into the sea and lo and behold, there were millions of tiny glowing lights around us. The most amazing thing I've ever seen in my life and my most stunning travel experience. There were sparks around my fingertips like little fireflies. They stayed on my skin for a while even when I lifted my hands above the surface. The more I moved the more they appeared, these miniature bright shiny lights, like in a fairytale.

I remembered I had seen signs offering plankton tours on Koh Rong island a few days before and there I was, experiencing it. Why pay $40 for something you can have for free?

This phenomenon happens because of the chemical reaction of an enzyme called luciferin and oxygen in fish, jellyfish, squids, fungi, bacteria and algae, as well as in some animals found on land, like fireflies. What caused the sea to sparkle at night in a bluish-green colour was phytoplankton which emit light when stresses, such as when waves crash or being otherwise agitated. Bioluminescence happens pretty much all over the world in shallow and warm salt water but whether you see it depends on time of the year, temperature of the water, light pollution, and luck. It has been spotted in Australia, Vietnam, Cambodia, Thailand, Indonesia, Malaysia, Maldives, Costa Rica, Puerto Rico, Trinidad, Jamaica, Florida, California, Washington and even in Europe. So if you want to attend the spectacle try Zeebrugge in Belguim or Norfolk in England. ;)