Now, the company has launched an incredible-looking tourist sub that can take 24 passengers, a pilot and a co-pilot down to 100-meter (328-ft) depths in air-conditioned comfort, providing panoramic views of the aquatic world through colossal 5.5-inch-thick (140-mm) acrylic windows. Where other subs offer restricted views, this thing is very close to a giant transparent tube, like a glass walkway through an aquarium, tall enough to stand in.