The Veersegat was 300 meters long the foundation for the caissons lies 11 meters below sea level and was 100 meters wide. This foundation was made of rocks, stones, pebbles an gravel of different sizes. On top of these layers the put giant rocks which could not be washed away by the sea. The foudation was made so that the caissons could be placed comepletely horizontal. In that way there would be no holes between the caisson.