Now that Link has learned to cooperate with Princess Ruto, it's time to search for the missing Zora's Sapphire. To achieve this goal Link will need to find a Boomerang buried somewhere withing Jabu-Jabu's sprawling gut.
Boomerang
Back on the first floor, carry the princess back to the room with sinking holes in the floor. On the opposite side is a door leading to an unusual area where twisting tentacles lurk. Holding Princess Ruto, step on the switch which is too strong to be pressed with Link's weight alone.
Parasitic Tentacles
To open another switch in this area, Link must drop the princess on the button and proceed without her. She won't appreciate being left behind, but she'll wait patiently anyway.
Bigocto
With all of the Parasitic Tentacles destroyed, Link and Princess Ruto can return to the room with holes in the floor and drop down the opening that was previously blocked by a green tentacle. The door on the floor below leads to the Zora's Sapphire!