The so-called surge phenomenon is a universal physical event that occurs when waves approach the shore line.
Waves in deep water (deeper than half the length of the wave) are essentially water particles moving in a circular motion.
As the waves approach the shore, they start "shoaling" as some of the water particles moving in a circular motion come into contact with the sea bed. This interaction with the sea bed elongates the circular motion into a horizontally elliptic shape as the particles flatten and stretch. This in turn amplifies the horizontal movement of the water particles in the near-shore area, creating a strong surge zone which is the optimal location for WaveRoller.
In addition to amplifying the back and forth movement of water, the near-shore area has other advantages that make it a good location for installing wave energy converters. For a more in-depth discussion on how near-shore and off-shore wave energy resources differ, visit Near-shore vs. Off-shore.