The Shell's Secret

The Shell's Secret, also called The Shellfish Secret,  is the sixth episode of Noki Bay in Super Mario Sunshine. The episode's objective is to climb up to a large shell and clear its secret course. After completing the episode once, the player can return to this episode to collect the Secret Shine Red Coins on the Half Shell

Layout
To access the secret course, Mario has to climb up the large pillars in the center of Noki Bay and use the ropes between them to jump higher. Several of the ropes have Wire Traps moving along them, with the blue ones simply moving along the rope and red ones that follow Mario. Alternatively, the player can climb up the mountainside and jump to the spiral platform across, then take the ropes to progress. Once Mario enters the purple shell, Shadow Mario appears to take FLUDD away and Mario is brought to the secret course.

The Shell's Secret is made up of several spinning and moving platforms. The player begins in a glass box that Mario has to Wall Jump out of, followed by jumping across a spinning green platform and a rotating yellow platform. The next set of platforms slide in and out of the wall, but the ends of them do not slide in all the way. The safest way to reach the first of these is by using a Side Somersault and Wall Jump against the wall to the right, but Mario can also reach it by Triple Jumping, the rest can be crossed with simple jumps. Afterward, the player needs to climb a pole then use a rope to jump onto an above platform. Mario then has to use a series of Side Somersaults and Wall Jumps to climb up to the top of the wooden structure. The next segment is made up of long, rotating blocks like the ones featured in The Secret of Ricco Tower, Mario can cross those by staying on the most level surface he can as usual. After two of these rotating platforms is a stack of spinning platforms Mario has to use the Side Somersault to climb up. At the top is a third rotating log, cross it to reach a platform with the Shine Sprite.