Ground improvement is an established technique in foundation engineering. In recent decades, modern methods of ground improvement have utilised explosives, impact energy, thermal treatment of the soil, vacuum consolidation, vibratory compaction technologies, stabilization and solidification of soft soils, as well as combined systems of ingenious grouting systems and deep mixing technique. Internationally, deep mixing techniques are often the chosen method for dealing with increasingly-demanding foundation problems. Initial experiences, using inventive new developments of soft soil deep mixing technologies and various advanced high pressure mixing methods, have proved successful both onshore and offshore. This publication illustrates a challenging example, sited in the Port of Antwerp, Belgium, of the design and construction of a large underwater embankment on very soft soil. This text will be a valuable reference case history for the geotechnical engineer, both from the academic's as well as from the practitioner's point of view.