Tidal Tempest

Tidal Tempest is the third Zone in Sonic the Hedgehog CD. The boss of the third zone is Dr. Robotnik in his Egg Mobile, attacking underwater.

Present
It is an underwater region that strongly resembles the Labyrinth Zone. It rests at the base of many volcanoes and rocky structures only seen at the very beginning of the Present zones. Pipes carry water from one area to another, with stone pillars adorning certain parts of the zone. The water elevation is normal in the Present, giving the zone a greenish/clear tint when entered.

Past
In the past, it is an underground cavern that has been untouched by mankind or machinery; strangely, it features pipes similar to those in the present. Stone pillars take a different shape here and the water level is fairly low, giving the caverns a darkened tint if stepped into.

Bad Future
The Bad Future shows an over-industrialized, non-functional and corroded water plant. Broken-down machines and ruined stone pillars are featured here, and years of pollution have made the water toxic and unsafe (resulting in a reddish tint when entered).

Good Future
In the Good Future it is a fully operational, turquoise aquarium that harbors much plant life in hydroponic cases. Fish swim freely through the water, which features a pleasant light-turquoise tint when entered. The water level is at its highest point in both futures.

Trivia

 * All Badniks in Tidal Tempest are based on insects.
 * The Yago Badnik is a dragonfly larva, while the Tonbo is a dragonfly, but it is highly unlikely that the Yago becomes a Tonbo, as the Yago has a broken future form.
 * Due to a flaw in emulating the graphics card, the Gems port of Sonic CD made the water of the Present timeline clear as opposed to green from the original and 2011 re-release versions.
 * The music for Tidal Tempest Past is remixed while in Metropolis of Sonic Chronicles: The Dark Brotherhood Chapter 6 after Angel Island crashed into the said city.