Kelp Forest exhibit
The 28-foot-tall (8.5 m) 333,000-US-gallon (1,260,000 l; 277,000 imp gal) Kelp Forest exhibit was designed as the centerpiece of the aquarium, and was the first exhibit in the world to include a living kelp forest. In addition to the bay water provided to all tanks, a surge machine at the top of this exhibit provides the constant water motion that kelp requires. The top of the tank is open, and was situated to maximize its exposure to sunlight during the day, thus further mimicking the bay. Eighty species of seaweeds grow in this exhibit, some of which have also entered the aquarium through the water from the bay rather than being deliberately planted. The kelp in this exhibit grows about 4 inches (100 mm) per day, and requires divers to trim it once a week.
Each of the main windows in this exhibit is 8 feet (2.4 m) wide, 16 feet (4.9 m) tall, and 7.5 inches (190 mm) thick.