The main objective of this research was to assess the impact of different placement methods, with different packing densities, on the stability of double layered Antifer-block armour layers. This was done by experimental research in the wave-flume of the Fluid mechanics laboratory of the Faculty of Civil Engineering and Geosciences at Delft University of Technology. 17 experiments were performed with packing densities between 44.8 and 61.1 percent. For every experiment the under layer, toe and armour layer were rebuilt. The placed Antifer layer was tested with eight irregular wave series with increasing significant wave heights from 9cm up to 20cm. From these experiments followed that regular placement methods behave more stable than irregular placement methods with a similar packing density. Also the more irregular (less accurate) positioning of blocks within a regular placement method caused a decrease in stability. Higher packing densities for equal placement methods lead to higher stabilities