Footage shows a massive funnel-shaped waterspout amid dark storm clouds raging off the coast of Rayong province, Thailand on August 20.

Two types of tornadoes form at sea - tornadic waterspouts and fair-weather waterspouts. Tornadic waterspouts form from thunderstorms, just like land tornadoes, while fair-weather waterspouts are typically smaller and less powerful without the need for storms.

Both types of waterspout tornadoes are created when there is a strong difference in air pressure between the surface of the water and the air above it. This difference in pressure creates an updraft, which draws air from the surface of the water into the atmosphere. As the air rises, it cools and condenses, forming a cloud. The cloud can then rotate, forming a waterspout.

It is rare for waterspouts to cause severe damage. However, in August 2023 two tourists were killed and six injured when a waterspout tornado hit their boat on an estuary river in Phetchaburi, southern Thailand.