ACement structures as per the following conditions:
1. The outer surface must be covered with a layer of rocks
2. The materials used must be resistant to marine environment conditions, such as the salinity resistant cement 450 SRC, used in concrete to build the structure.
3. Natural rocks
4. It is prohibited to use structures and models made of plastic, fiberglass and other forms made of dangerous chemicals and hydrocarbons harmful to human health and marine life.