The Coastalock now has a consolidated set of hydraulic design recommendations, the result of a multi-institutional research programme bringing together the University of Ottawa, TU Delft, the National Research Council of Canada, and ECOncrete.

For engineers considering the unit for a coastal protection project, it represents an important step forward. It is the first time results from multiple independent physical modelling programmes have been consolidated into a single set of design recommendations for Coastalock, building on a growing body of testing across leading coastal engineering laboratories worldwide.

Wave flume testing of Coastalock single-layer armor for low-crested and submerged breakwaters, carried out at NRC Canada with the University of Ottawa in 2023 at 1:15 scale on a permeable core.

Since its development, Coastalock has been the subject of a series of independent physical modelling programmes at institutions including TU Delft, the University of Ottawa and NRC Canada, and others worldwide. Each programme has added to the evidence base for the unit’s hydraulic performance across different configurations, slopes, and wave conditions. The ICCE 2026 paper, led by Dr. Serim Dogaç Sayar, synthesises those results for the first time into design-oriented recommendations for the unit. Cross-validated across different test setups and methodologies, the conclusions provide the kind of robustness that makes design recommendations usable in practice.

The study covers revetments and emergent rubble mound breakwaters across a range of front slopes, armour spacings, and hydraulic conditions. It identifies the key parameters engineers need: an optimum armour spacing for preliminary design, stability numbers consistent with established single-layer systems, and roughness factors that allow overtopping to be assessed using standard EurOtop formulations. Coastalock fits into existing design workflows rather than requiring new ones.

Wave flume test of Coastalock single-layer armor with a top rock layer, conducted at NRC Canada in 2024 to evaluate slope stability at 1:15 scale.

At the Port of San Diego, where Coastalock has been in place since 2021, four years of monitoring show measurable gains in species richness and biomass compared to adjacent riprap. These design recommendations complete the picture; hydraulic performance validated independently across multiple institutions, ecological performance validated in the field. 

The findings will be presented by Dr. Serim Dogaç Sayar at the 39th International Conference on Coastal Engineering (ICCE 2026), Galveston, Texas, 17–22 May 2026.