CONTENTS 



TABLES — Continued 



Page 



3 Observed versus predicted relative crest elevations for 



monochromatic waves 20 



4 Coefficients for estimating the duration of wave crests 28 



5 Observed versus predicted relative crest durations 28 



6 Selected irregular wave crest elevation data . 31 



7 Selected irregular wave crest data for waves breaking on a 



1 on 30 slope 33 



8 Values of Af for levels of probability of exceedance for 



irregular waves derived from 122 laboratory experiments 38 



9 Values of A^ for levels of probability of exceedance for 



irregular waves on a 1 on 30 laboratory slope 38 



10 Summary of prototype wave conditions ^° 



11 Values of crest heights observed and predicted for waves 



at Duck, North Carolina ^6 



FIGURES 



1 Example of an extremely nonlinear wave condition 10 



2 Predicted monochromatic wave profile H 



3 Experimental setup in CERC's 4.5-meter-wide tank 12 



4 Sample of water level time histories taken at four gages during 



an irregular wave test 13 



5 Experimental setup in CERC's 0.9-meter -wide tank 1^ 



6 Experimental setup in CERC's 0.4-meter-wide tank 15 



7 Observed and predicted wave spectra 1° 



8 Empirical coefficients A2 and A3 for estimating Hc/^^ 19 



9 Effect of beach slope on relative wave crest elevation 21 



10 Effect of beach slope on breaker crest elevation 22 



11 Wave crest elevation for constant values of wave steepness 23 



12 Wave crest elevation for constant values of H/H^ 25 



13 n„/d for constant values of wave height to depth 26 



14 Empirical parameters for estimating wave crest durations 27 



15 Values of dimensionless wave crest duration 29 



16 Sample of irregular wave time histories 30 



17 Variation in wave crest elevation for a 1 on 30 slope 33 



18 Sample of water level time histories for irregular waves at 



selected locations along a 1 on 30 slope 34 



5 



