A close-up technical macro photograph of the base of an underwater engineering rig resting on a concrete pool floor. A large 3-inch diameter white PVC pipe is bolted horizontally to a gray steel strut frame via heavy-duty cushioned pipe clamps. Branching off the PVC pipe are large 3-inch to 4-inch wide bell-shaped PVC adapter cups pointing downward toward the floor. Huge, distinct, clear 4-inch wide air bubbles are swelling up and detaching from the rims of the cups, rising vertically through the water. A heavy 40-pound concrete ballast block is bolted across the steel frame underneath to hold it down. High clarity, photorealistic underwater construction documentation style. Mehr sehen