What are Reef Balls?
Reef Balls are artificial reef modules with form and function designed to be as close to nature as possible. They are made from concrete poured into a fiberglass mold containing a central Polyform buoy and various inflatable side balls that provide holes and cavities.

MariLim is authorized Reef Ball contractor for

We provide all kinds of service including training, planning, manufacturing, deployment, and monitoring.

These are the most common dimensions and their approximate parameters (width height):

Name Size (m) Holes Weight (kg)
Oyster 0.5 x 0.3 6-8 11-20
Lo-Pro 0.6 x 0.5 6-10 23-40
Bay 0.9 x 0.6 10-16 170-340
Pallet 1.2 x 0.9 17-24 680-1000
Reef 1.8 x 1.2 29-34 1360-2200
Ultra 1.8 x 1.4 29-34 1800-2700

Oyster Balls


Marine friendly concrete

Concrete with a pH similar to seawater makes Reef Balls best suitable for settlement of marine life. A specific concrete admixture gives the modules high strength.

Floating deployment

The Polyform buoy needed to build the modules can be used to keep them afloat for towing and safe placement.

Unique hole size & placement

With a variable size, shape, and number of holes, Reef Balls imitate nature to a great extent.

Surface textures

Different methods of surface treatment enhance the settlement of larvae and other small life forms. Thousands of small pits or a rough texture can easily be modeled.


More than half of the weight is in the lower part of the module near the sea floor. This enables Reef Balls to withstand heavy storms even in shallow waters.

MariLim® aquatic research
WischhofstraBe 1 -3, building 11 - 24148 Kiel / Germany
Fon: +49 (0)431 7207081 - Fax: +49 (0)431 7207085
e-mail: tmeyer@marilim.de  - web: www.marilim.de