Using the equation below and Table 8-4 at the bottom of this post, the estimated shoreward speed of a good, surfable 6-foot wave would be approximately 11 mph.
Where v = velocity, g = gravitational acceleration, d = depth and λ is wavelength.
Based on the table below, I would say good surfing waves are "plunging" waves. The table provides ratios of water depth to wave heights for different types of breaker waves. A simple calculation where d = water depth and h = wave height can be used to estimate water depth for the different the types of wave described in the table. For plunging waves, a 6-foot wave would break in
d/h = 0.9
d/6 = 0.9
d = 0.9 x 6 = 5.4 ft of water.
Use 5.4 feet for d (depth) in the shallow water wave velocity equation above. Velocity of a 6-foot wave moving toward shore would be aproximately 13.1 mph.
For an expanded discussion about wave and surfing speeds, click the following link:
http://bgsurfphysics.blogspot. com/2018/08/wave-surfing- speeds.html
Wave Velocities (C) for Selected Wave Heights and Types
For an expanded discussion about wave and surfing speeds, click the following link:
http://bgsurfphysics.blogspot.
Wave Velocities (C) for Selected Wave Heights and Types