Shark tunnel

A shark tunnel (or aquarium tunnel or acrylic tunnel or exhibit tunnel) is an underwater tunnel that passes through an aquarium, typically with sharks and related aquatic life. They are usually made of thick acrylic glass.

Most aquarium tunnels are cylindrical in shape, though tunnels can be made elliptical (to make them wider and still keep the top of the tunnel closer to the visitors), or even square.

This list is sorted alphabetically by aquarium name.

† — Estimated based on top of tunnel being 4 ft (1.2 m) under the surface and 9 ft (2.7 m) to bottom of tunnel.

...
Wikipedia