The Water Key is a special progression item in the Second Sea used to unlock Sharkman Karate, making it an essential item for players upgrading from Water Kung Fu. It is obtained by defeating the Tide Keeper boss, who can be found at the back of Forgotten Island.

Obtainment:

The Water Key is obtained by defeating the Lv. 1475 Tide Keeper boss, who is located on Forgotten Island in the Second Sea. It is a boss drop, so obtaining it is not guaranteed and may require multiple defeats before it drops.
Usage:
The Water Key is used to unlock training for Sharkman Karate by giving it to the Sharkman Teacher. After the key has been handed over, it is consumed permanently, and the player will never need to obtain or use another Water Key again.
Additional Information:
• The Water Key is lost if the player dies or leaves the game before giving it to the Sharkman Teacher, so it is best to use it as soon as it drops.

• The item is only required once to unlock Sharkman Karate. After it has been used, the player never needs to obtain another Water Key.