Zora Scale

Zora Scales are fragments of the skins of Zoras. They seem to hold the aquatic identity of the Zoras, as a not-Zora in the possession of one finds themself better adapted to water.

Ocarina of Time
Ocarina of Time features both the Silver Scale and the Golden Scale. While the Silver Scale is stated to be a Zora Scale, the Golden Scale is not and can only be assumed to be one based on its many similarities to the Silver Scale.

Silver Scale
Link's own abilities allowed him to swim downwards for no more than three seconds, in distance three meters. When he reached Zora's Domain, he was invited for a diving game by one of the Zoras. The award for winning the game was the Silver Scale, which appropriately enhanced Link's diving capabilities. Instead of three, he could then dive for a total of six seconds, in distance six meters.

Golden Scale
An enhanced version of the Silver Scale, the Golden Scale was the award for catching a record-breaking fish at the fishing hole in Lake Hylia during the future years. The time and depth of a dive that could be archieved with the Golden Scale reached up to nine.

Unlike obtaining the Silver Scale, gaining the Golden Scale is optional.

Oracle of Ages
In Oracle of Ages, the Zora Scale is given to Link by a Zora after Link defeats Plasmarine and gets the Rolling Sea from Jabu Jabu's Belly. It is used for two things. First, it is needed to get into the Sea of Storms. Also, when Link gives the Zora Scale to the Piratian captain, Link gets the Tokay Eyeball.

Twilight Princes
In Twilight Princess, the Zora Armor is made of Zora scales. It is created by King Zora himself for the destined Hero. Interestingly, the Zora Armor makes its wearer vunerable to fire and ice, weaknesses Majora's Mask's Zora Mask established to belong to the Zora race.

Phantom Hourglass
Phantom Hourglass' Zora Scales are among the treasures that can be sold on Mercay Island to the Teller of Treasures for a fixed, random amount of Rupees. It is also a highly valued commodity among members of the Ho Ho Tribe.