Ascend the Ethereal Tower

To ascend the Ethereal Tower, activate lanterns in the sand, then proceed to the hill with statues and more lanterns. Branch off left to hop up to a higher hill, activating additional lanterns at the top. Follow the path through an archway, then left to a tall rock with jellyfish. Hop to the top and use Water Rail to glide to a tower containing a water orb.

Activating this water orb spawns the first part of a bridge. Return to the area where the staircase is building, go up into the tower, and take the chain upwards. From the first floating boat, jump onto the jellyfish to your right and use Water Rail to glide into an upside-down tower to find a chest. After riding the gold chain upwards, reach the first boat, then follow the path left using Water Rail and jellyfish. A ring of paper lanterns near a tower indicates a secret shell. After collecting it, use the shortcut drain behind it to teleport to a tower with another chest.

From the floating island leading to the time trial, hop back to the floating boat. Continue right across jellyfish and paper lanterns to a tower with lights on either side of the archways. Inside, activate all lanterns in the pool to create a boost strip. Use it to boost higher into the tower, then enter the shortcut porthole on the higher ledge.