This is the moment tourists spotted a terrifying waterspout forming off the coast of Phuket, Thailand.

The holidaymakers were riding a yacht when they saw the dark weather phenomenon swirling in the horizon. Footage shows the giant water column extending from the clouds down to the waters of Phuket on April 20.

Tourist Talob Gob said: 'Everybody came for a holiday to see beautiful sunsets, but we saw this instead. It was very scary.'

Waterspout tornadoes form when wind merges from opposite directions near the water’s surface, creating a small area of spin. Warm air at the surface causes the spinning air to rotate faster and it starts to rise – picking up water at the same time and forming a cloud.

Sometimes the air spins so fast that it stretches and a funnel appears from the water to the thunderstorm cloud above.

Waterspouts are generally not dangerous but they can be a risk for aircraft flying through the area and for coral reefs and marine life in the water immediately below. Sailors should also try to avoid waterspouts – as the consequences of floating into one could be disastrous.