A wave that breaks over a rock seabed or a coral reef is known as a reef break. The waves that it produces are usually the typical ones that get featured in surfing videos. A reef break occurs when an underwater obstruction suddenly rises above the sea floor which causes the swell to peak and throw out a pitching lip, creating a hollow or tubing.

Reef Break wave

Aside from coral reefs, the obstruction can also be a rock shelf or a submerged piece of wreckage. The waves can be dangerous if a surfer wipes out in a bad way but, more often than not, it is the perfect kind of wave to surf on. In Britain, you can find good reef breaks in Porthleven, Kimmeridge, and Thurso East.