*4.6. Estimation of Wave Heights*

A summary of key data is provided (Table 7), pertaining to average boulder size and maximum boulder size from the four transects in barrier #1 and two transects in barrier #2 as correlated with weight calculated on the basis of specific gravity for andesite. These data are applied to estimate the wave heights required to transport boulders from the bedrock source in sea cliffs to their resting place embedded in the natural breakwaters. The estimated wave height needed to move the largest bolder encountered in Transect 1a amounts to 7 m, although the average computed for the 25 boulders in that sample amounts to 6.3 m. Average boulder size generally declines through the four transects from barrier #1, as does the average wave height estimated to move those boulders. Regarding barrier #2, the average boulder size declines from transect 2a to 2b and so does the average wave height estimated to move those boulders. However, there is no difference between the largest boulders from the two transects with respect to maximum size and estimated wave height required to shift those boulders.


**Table 7.** Summary data from Tables 1–6 showing maximum boulder size and estimated weight compared to the average values for all boulders (N = 25) from each of transects 1–6 together with calculated values for wave heights estimated as necessary for boulder mobility.
