How do barrel waves form?

Answer 1

Here is a simple answer to how do barrels form? As a wave gets closer to land the water gets more shallow causing the wave to start getting steeper. As it approaches the reef or whatever causes it to break, the wave starts getting steeper and taller. As this happens the wave starts to peak, causing the lip of the wave to be pulled down to the bottom wave by gravity. When something gets too tall gravity pulls it down; making a barrel.

Answer 2

Barrel waves form when the crest of the wave curls over and creates a tube-like hollow shape as it breaks. This occurs when the wave breaks over a steep underwater contour, like a reef or sandbar, causing the crest to fold over and form a barrel. Surfers often seek out barrel waves for the exhilarating experience of riding inside the tube.