Go to the south side of the nuclear power plant where you can see two roads encircling a green circle on the map to find a toxic waste dump pool. Go inside to find barrels and cars sunk inside. Swim over to the caged-off sewer tunnel to find blow-up dolls, and one floating around you. Swim around the center and look below to find two skeletons inside and laying around the old cars, and one trapped in a picnic bench. There are also some big fish swimming under you, which is rarely seen unless you are in a secret area such as Volution Island waters.