Coral Cave is the third stage of Sonic Rush Adventure. As with other stages in the game, Coral Cave consists of two standard Acts followed by a dedicated boss Act. Red Material can be found here.
After Machine Labyrinth made Bronze Material available for ship building, Tails constructs the Ocean Tornado, a sailboat with greater range than the Wave Cyclone. Just before setting on their maiden voyage, Sonic, Tails, and Marine run into Colonel, another koala of the Coconut Crew. He divulges that there's an island which bears investigation past the shallows to the west of Machine Labyrinth; so this is where the heroes sail.
En route, they are ambushed by Johnny, who challenges Sonic to a race in the first Battle Race. Further on, the trio find Hidden Island 1; a small atoll with a mysterious altar on it. Marine recklessly messes around with the ancient plinth - which somehow causes Coral Cave to rise out of the water. As usual, Marine wants to rush in at the head of the group, but Sonic and Tails notice footprints at the cave entrance...
A sunken grotto filled with crystalline coral, the cave rises up from below the waves in the extreme west of the game map. Giant pulleys and minecarts filled with colourful gems serve as testament to the jeweled wealth hidden beneath the stage's placid waves. The player should watch out for the massive stalactites falling from above; while knocking down a rock from above is often necessary to progress, the falling structures do have a tendency to crush the player.
- Mine Cart - Must be pushed to get it going, which is easier to do if the player Boosts into it. The Mine Cart goes forward automatically, but it can be slowed down by pressing , and the player can also jump with it. At intersections, press or to choose a different path if necessary. In the 3D sections, jump over mines and to pick up Rings.
- Pulley with Hook - Huge pulley with a hook and rope at the end, it sends the player down and then up, and they can trick off it like a Spring. The little known fact is the player should hit before reaching the hook when they are on the pulley, because for some reason that part counts as a Rail and can help fill the Tension Gauge.
- Wooden arm - Running into it will simply take the player up to another elevation in the Act. The player can't do Trick Actions off it.
- Rocks suspended with Coral - Falling rocks are instant death, but they can be used as a platform. If it's red Coral suspending the Rock, then the player needs to either Jump, use a Trick Action, or jump while Boosting into the coral to make the rock fall. If the coral is green, it falls on its own; the player just need to stand back so they don't get crushed.
- Green Crystals - Gigantic shards of green crystal which launch the player in the direction perpendicular to the surface touched. Trick Actions can also be performed off them.
||Barrier Angler — Angler robot that charges up a ball of electricity in front of them. Boost or Spin/Burst Dash into them.
||Eleki Angler — Shoots out two energy balls towards the player's direction. Easier to jump on than the red ones.
||Rapid Crab — Crab robots that rapidly thrust their claws into the air.
||Dive Bat — Bat robots similar to the Pteras in Plant Kingdom. They just hover and swoop.