The Secret Sea is an esoteric and hidden area of Orange Ocean. Ever since the Halberd crashed here, the place was locked away, and only the five Star Seals could penetrate the magic barrier and grant access to the Secret Sea. During the events of the game, the Halberd still remains sunken here from the events of Revenge of Meta Knight, but it eventually resurfaces when Kirby and Meta Knight engage in combat.
The sea is geographically similar to the rest of its greater location, Orange Ocean. It consists of many small, tropical islands, deep undersea reefs and ares with strong wind currents. Some of the area also has the trademark sunset of Orange Ocean, though this is not visible in the depths of the sea.
If Kirby obtains Bomb's and Sword's Ability Scrolls, he can mix the following abilities:
- Stage 1
- Secret Sounds: in the first room with water currents, Kirby should swim up the second side path he encounters, being careful not to be swept away by the current; this path will lead to the chest.
- White Spray Paint: in the room with the Foleys, Kirby must use the Bomb ability to set off a Bomb Block located to the very left of the area, past some spikes; this will open a path that leads to the chest.
- Throw Ability Scroll: the large Treasure Chest is located in the final room; if Kirby does not intercept Storo in time, he will need to retrieve the chest from the Squeak hideout.
- Stage 2
- Sapphire Spray Paint: in the room with the wind currents, Kirby must use the Metal ability bubble he obtained while riding the Warp Star to move against the wind; the chest is located in a nook of a cloud near the right side of the room.
- Graphic Piece: in the room after the fight with Buboo, the chest is located in the center of the cloud mass at the top of the room; Kirby must use a suitable ability to burn through the clouds in order to obtain the chest.
- Ghost Medal Piece: the large Treasure Chest is located in the final room; if Kirby does not intercept Doc in time, he will need to retrieve the chest from the Squeak hideout.
- Stage 3
- Graphic Piece: in the first room, Kirby must use the Fire ability to access the door in the bottom-left corner of the room by burning through the clouds blocking it; the chest is located in the next room.
- Spunky Notes: in the room where Kirby descends on moving platforms, he must use the Beam ability to set off a Bomb Block placed inside a wall; when the chest drops down, he must be careful to obtain it before the platform the chest is placed on drops.
- Bomb Ability Scroll: the large Treasure Chest is located in the final room; Kirby must race Spinni in his dive downwards to obtain it.
- Stage 4
- Ocean Spray Paint: in the second room of the level, Kirby should take the upper path, which will lead him to a switch; after pressing it, he must hurry downwards to collect the chest before it falls into a pit.
- Magic Ability Scroll: in the first room of the sunken Halberd, Kirby must use the Spark ability to send sparks through the metallic floor and hit a Bomb Block on the left side of the room; this opens up a path leading to a barrel, in which the chest is located.
- Secret Door Key: in the final room, Kirby must obtain the large Treasure Chest by defeating the Squeaker who is carrying it.
- Stage 5
- Stage EX
- Secret Map Piece: at the second choice of three doors, Kirby must take the middle door; this eventually leads to a room where Kirby must hit the top switch without hitting the bottom switch, defeating the Gold Waddle Dee to obtain the chest.
- Graphic Piece: when given the choice of two doors, Kirby should take the right one, which will lead him to the chest.
- Vitality Half: the large Treasure Chest is located on a moving platform in the final room.