Zig Zag Reef:
The reef is located at 360 40’ 52” S, 1740 45’ 14.8” E in 5.5 m at minimum spring low tides. It comprises twelve concrete hemispherical shells made of 60 MPa concrete with microsilca added. There are nine Bay Balls [mass approximately 300 kg, height 0.7 m, base diameter 1.0 m with about 10 piercings] in a N – S line. At the Northern end, there is a Pallet Ball [mass approximately 1200 kg height 0.9 m; base diameter 1.2m with about 15 piercings]. ]. At the Southern end, there are two further Pallet Balls; one with a 30x30 cm slate plate attached to a vertical surface and the other with a plate attached to close the top hole of the unit; i.e. in a horizontal position. These slates are the same as the ones utilised by current E. O. S. intertidal studies. Placement took approximately 6 weeks because of tide/weather/logistical constraints. All 12 units lie on a N – S line parallel to the beach with an angle of approximately 450 between this line and the zigzags and about 1.0 metre between each.