Linear Wave Theory

Linear wave theory is also known as:

• Airy theory;
• Sinusoidal wave theory;
•  Small amplitude wave theory.

Description:

• It has only single sinusoidal component;
• It is the simplest wave theory obtained by taking the wave height, H to me much smaller than both the wave length, λ and water depth, d. 
• Wave crest height, AC = Wave trough height, AT and is denoted the wave amplitude, A, hence H=2A.
• Linear wave theory is the first approximation to the wave motion. In order to achieve theoretical results closer to the reality requires to solve the equations to higher perturbations (non-linear system).