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ARC Marine Reef Cubes®

Arc Marine Reef Cubes
Reef Cubes ready for deployment in the Offshore Test Site

General description and use

Reef Cubes® are specifically engineered for offshore projects to protect subsea infrastructure and restore the marine habitat. They are made of a carbon neutral, marine friendly concrete which is robust and long-lasting (max 500 years). They can also be made with finite biodegradable materials if needed for certain applications, however ARC Marine is pioneering the long-term restorative techniques that the ocean needs to prevent an ecosystem collapse. The 3D shape of Reef Cubes consists of one central chamber and six passageways, through which the marine life can enter into the structure. Sediment can enter and exit the chamber according to the natural water flow and sediment movement, and due to the flexibility in the design it can be engineered to trap sediment and stabilise the seabed.. The surface of the cubes has a pH similar to that of the ocean and has ecologically enhanced surface textures making it suitable for multiple organisms to settle and establish itself.

The stacking of the cubes creates diverse living space for fish, crabs and lobsters and other marine species attracted to (natural) reefs. Reef Cubes® provide food and shelter for marine flora and fauna in all stages of their life cycles from spat & juvenile stages all the way to adult phases. They provide spawning/nursing grounds for both fish and invertebrates. They help create an increase in biomass and support the reestablishment of ecosystems as well as providing certain parameters for specific marine species (ARCMarine, 2020). ARC Marine has two patents granted in the UK and is awaiting decision covering the E.U & 10 other countries including US, China, Australia and Brazil.

The Reef Cubes® from ARC Marine are made from a by-product from the quarrying industry and a Portland Cement replacement, their cement uses 90% less carbon and they can use carbon capture materials to be carbon neutral & even carbon negative. They consist of 98% fully recycled materials and certified toxic free. They use sand and aggregate from left over quarry spoils to promote a circular economy approach to construction. If needed, Reef Cubes® can be 100% recycled during decommissioning and used as a secondary aggregate for the construction industry. They are designed and proven to resist chemicals and saltwater and last longer than ordinary cement concrete (ARC Marine, 2020).

The cubes can be used for cable and pipeline protection & crossovers but also as granite replacement/ enhancement for scour protection around offshore oil and gas installations or offshore wind farms, including rock berms. They can be used in other industries which can help marine spatial planning such as coastal defence, eco moorings, sacrificial anchors, aquaculture, reef tourism, mangrove restoration and bottom trawling deterrents in Marine Protected Areas, as well as in reef restoration projects or nature-inclusive designs.

A Reef Cube in use
A Reef Cube in use. Photograph: ARC Marine.


The texture of the cubes is made quite similar to replicate natural reefs and accelerate restoration. The use of advanced casting techniques is unique to ARC Marine and allows them to build complex shapes and sizes. (ARCMarine, 2020). The combinations possible with Reef Cubes® is limitless and smaller cubes can be placed inside larger cubes to give great complexity and to increase mass. Formations can be designed around specific ecological species such as Cod, lobsters, crab, oysters etc. The specific material can be adjusted to the clients wishes and technical requirements required by subsea engineers and regulators. Additions to the Reef Cubes such as recycled shell-material can be made to create an even more natural surface and to enhance the settlement of flat native oysters or blue mussels. The Reef Cubes® can be made in different sizes ranging from 15cm to 2m and can be stacked or filled with smaller Reef Cubes®. The weight range is from 5kg to about 6 tonnes with bigger units planned. (European Commission, 2020).

Stability and placement

The shape of the Reef Cube® is stable and robust in both shallow and deep water (Deployment Matters, 2020). Its stackable & interlocking features make it particularly suitable for complex marine habitats which increases the habitat space. Reef Cubes® disrupt the incoming waves and current, their cube shape lowers the permeability whilst trapping the sediment. Its foundation is stabilized and they are designed to be left in place. However OSPAR still has to accept the cubes as suitable for long term deployment without recovery liability (ARC Marine, 2020).

ARC Marine is capable of deploying globally through licensing agreements and offers full reef planning, design, construction, deployment, monitoring and stewardship support. They are compliant with Nature Inclusive design, civil engineering standards and marine concrete and lifting specification approval . Furthermore, they are experienced in traditional deployment techniques and pioneering new low costs and efficient solutions. (Deployment Matters, 2020).


Reef Cube Practicalities

Examples of use

Link to the North Sea Farm Offshore Test Site:



Brixham Laboratory

Freshwater Quarry

Brixham, Devon


Phone: +441803 659195



ArcMarine. (2020). Reef Cubes – the building blocks for saving the ocean - ARC Marine - Accelerating Reef Creation. Retrieved October 2, 2020, from

Deployment Matters. (2020). Reef Cubes. Retrieved October 2, 2020, from

European Commission. (2020). ARC Marine LTD | Maritime Forum. Retrieved October 2, 2020, fr om

A Thank you to Tom Birbeck from ARC Marine in helping to create this text.

ARC Marine Reef Cubes®

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Related species:

European lobster