Water Key Blox Fruits: unlock Sharkman Karate

The Water Key is an Uncommon item in the Second Sea: it's proof that you've defeated the Tide Keeper. It serves only one purpose, unlocking training in Sharkman Karate from the Sharkman Teacher, and only once per account.

How to get it

Defeat the Tide Keeper, the level 1475 boss located at the back of Forgotten Island (Second Sea).

Be aware, the source is inconsistent about the drop rate: its box states a 5% drop, while the page body presents the key as the normal victory reward with no percentage given. Plan for possibly multiple attempts on the boss.

What it's used for

Give the Water Key to the Sharkman Teacher: he'll unlock training in Sharkman Karate for you.
Once handed over, it's never requested again. It's a single-use item per account: no point in farming another one later.

The trap to avoid

You lose the Water Key if you die, or if you quit the game before handing it to the Sharkman Teacher. The reflex to have: go see the NPC immediately after defeating the Tide Keeper, without detour and without taking risks along the way.

Did you know

Visually, it's a small luminous glint surrounded by water effects, not a classic key.
It's one of the rare keys in the game directly linked to unlocking a fighting style.