Rip Rap (R3
As one of the largest varieties of rip rap, R7 is 18 to 30 inches, and R8 is 24 to 42 inches. In bigger bodies of water with rapid currents, R7 and R8 provide the best erosion protection. These varieties are the best options for restoring a bank that has already started to erode. You can also use them to fill in large ditches and holes.