Armoured slopes are commonly used in coastal structures to dissipate wave energy and protect adjacent infrastructure. To limit the height of these slopes in an efficient manner, regularly a concrete crest wall is placed at the upper part of the slope. Understanding the loads on these crest walls is essential for the design of coastal protection works. Conducting scaled physical model tests is a well established approach to confirm and optimise the design of coastal structures, albeit time consuming, scattered, and costly. This study aims to investigate the use of compact, focused wave signals in comparison to the common practice of using wave signals typically comprising a thousand waves in physical model tests. The physical model tests conducted in this study revealed that a compact wave signal was able to reproduce the extreme hydraulic response recorded during the simulation of a thousand irregular waves. This was observed in terms of sliding failure and extreme pressures exerted at the front vertical wall of the model crest wall. Results showed that the shape of the pressure signals, pressure distributions and integrated forces are reasonably well reproduced during focused waves. This suggests that this approach is promising for reproducing extreme responses at crest walls using focused waves; thus, resulting in reduced testing times. However, findings so far cannot support the use of this approach as a standalone tool for this application.