Air Cavities video cover

Watch the video about Damen Air Cavity System

Lowering the ship resistance results in the reduction of the fuel/energy consumption and emissions. The hull optimization generally helps to reduce the wave making and pressure resistance whereas the frictional resistance is considered as given and it is proportional to the wetted area.

Damen Air Cavity System (DACS) forms stable air cavities on the flat bottom of a ship reducing the wetted area. This results in a significant reduction in water resistance. The system has a high overall efficiency and can be used on ships for fuel consumption and emission reduction. For hybrid or electric ships the system can reduce the size of the energy generation and storage system or extend the vessel’s range.

DACS originated from a research project conducted at the Delft University of Technology (TU Delft) in the Netherlands.



The system can be retrofitted as well as installed on new built vessels.

DACS Components

  • Bridge control and alarm panel
  • Air compressor
  • Starter/junction box
  • Automated air valves
  • Air pipe work steel and/or plastic
  • Cavitators – transversal profiles on the bottom
  • Skegs – longitudinal profiles on the bottom



Inland waterway ships

Inland waterway ships have large flat bottom area and they are sailing at relatively low speed, often in shallow water. This is why for this type of ships the relative fuel consumption reduction by DACS is the highest. The fuel savings and emission reduction for this type of ships is typically 10-20%. In shallow water the effect is the highest as model test results show. The system increases the draught of a vessel by approximately 50-100mm and it is suitable for ships that operate in the areas where the grounding is not likely to happen.

Scale model of an inland waterway vessel equipped with DACS

Air cavities formed on the bottom.
The tests are conducted at DST, Germany

Full scale feasibility tests with a pontoon

Seagoing ships

The system is suitable for seagoing vessels. The savings due to the system depend on the flat bottom area, operational speed and draught of a vessel. The largest absolute savings are expected on the vessels with a large flat bottom area or the vessels sailing at high speed.

Scale model of a seagoing passenger vessel equipped with DACS

The tests are conducted at MARIN, the Netherlands



  • Lowers fuel consumption
  • Reduces pollutions
  • Reduces negative effect of the fouling on resistance
  • Can be accounted in EEDI
  • Reduces propeller load at the same speed and by that reduces propeller induced noise and vibrations
  • Qualified for EIA tax reduction (for Dutch flag vessels only)
River cruise vessel


Damen customer finance

Damen Customer Finance offers a wide range of financing arrangements. These are available for any type of vessel, equipment or related services, including the prefabricated shipbuilding kits supplied by the Damen Technical Cooperation department.

Damen’s Customer Finance facilities are not just for privately-owned, small and medium-sized companies, we also assist government bodies such as coastguards, police and port authorities. Damen maintains relations with all Netherlands-based commercial banks, as well as with numerous banks abroad. As a major client of the Dutch Export Credit Agency, Atradius, Damen is highly experienced in arranging export loans with export credit insurance facilities.

24/7 Spares & Services

Damen Parts Services offers competitive prices, efficient and cost-effective delivery and short response times. With our years of experience we have established strong buying power and an extensive supplier network. By expanding our network of global service hubs, we are able to shorten our response times. Our service goes beyond fast part delivery; we also offer different replenishment solutions resulting in having parts in stock just before you need them.

To minimise lifecycle costs and to improve a vessel’s performance, it’s crucial to have the right spare parts. Our Computerised Maintenance Management System (CMMS) allows stock control replenishment to be completely automated.



To support our customers on a 24/7 basis, Damen has created an online parts store on our Services Portal Here you can order directly from our online catalogue of spare parts. Our scope of supply is neither limited to Damen-vessels only, nor to the catalogue. If your required parts are not available online, we invite you to make online requests. Your services manager will gladly do what it takes to source the relevant component. With Damen as your partner you can experience the benefits of a one-stop-shop.


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