How to Find the Princess in Zora's Domain in Ocarina of Time

Make your way to the waterfall that blocks the entrance into Zora's Domain.

Play Zelda's Lullaby on the Ocarina and the water will part, allowing you to jump into the doorway.

Turn a sharp right down a pathway towards an interior pond. There are fish swimming around in the shallow water. Capture one of the fish in a bottle, you will need this later.

Head back up the pathway into the King's throne room. Inside, turn left past King Zora into the tunnel. You will see a Zora standing over the edge of the waterfall.

Accept the Zora's challenge to a diving competition. It costs 20 rupees, but you must complete and win this challenge at least once to find Princess Ruto. You will have 50 seconds to collect the five rupees the Zora drops into the water below.

Jump off the edge of the waterfall. Swim over and dive down onto each rupee to collect them all.

Run back up to the top of the waterfall and speak to the Zora. He will reward you with the "Silver Scale," allowing you to dive deeper into water.

Jump over the waterfall again and swim over to an underwater passageway. With your new ability, dive down and go through.

Swim out of the passage into Lake Hylia. There you will see a bottle. Target the bottle and dive down to collect it. There is a letter inside for King Zora. Swim back towards the passage and go through.

Head up to the King's chamber and show the bottle to the King. He will instruct you to rescue his daughter Princess Ruto and will move out of the way revealing a passage behind him.

Run up the path to the right that leads to where the King is sitting and go through the passage. This leads you out to Zora's Fountain and the Great Jabu-Jabu. Princess Ruto is inside.

Present the fish you caught earlier to Jabu-Jabu and his mouth will open. He will suck in the fish carrying you with it inside his mouth.

Run forward towards the back of Jabu-Jabu's mouth.

Hit the switch on the roof of his mouth with your slingshot and the back of his throat will open. Go through into the next area.

Avoid the jellyfish and run towards the next door. Inside you will find more jellyfish and to your right, Princess Ruto. Speak to her and she will allow you to pick her up to escort her out of Jabu-Jabu.