The Key Biscayne is a 2695 ton jack-up oil rig that sunk in 1983 ten nautical miles off Lancelin while being towed down the WA coast to be refitted. It is lying upside down in 42 Meters of water with the highest point at 26 Meters sloping from south to north. The rig is a shaped like a Pyramid the flat bottom facing the surface, the living quarters and all the machinery lie under the wreck, the legs, which broke off during the sinking lie to the side. It can be penetrated and is full of crays, however at 42 meters there isn't a lot of time to do that if you are on air. Nothing was salvaged from the rig when it went down due to the depth, so there is heaps to see. 

Birds-eye view (Mud-map)
While I was wearing my Dry-suit this old-salty only needed a 3mm vest. King of the castle Safety stop with the emergency Deco bottle at the ready
looking under a ledge See how many cray you can spot. Hint count the antennas
Under one of the foot supports Scorpion fish, be careful Coral on the top of the wreck