|Mask of Water Breathing|
|Power(s)||Let user breathe underwater|
|Kanoka||Shrink; Regeneration; Remove Poison|
|Notable Wearer(s)||The Toa Mata (formerly)|
- "Mask of Water Breathing; big help when there's no water anywhere around."
- —Gali, BIONICLE Legends 10: Swamp of Secrets
The Kanohi Kaukau was the Mask of Water Breathing, sometimes called the Mask of Water. It gave its user the power to breathe only water, albeit only to a certain depth and for a limited amount of time.
Kaukau were carved out of a mixture of Shrink, Regeneration and Remove Poison Kanoka on Metru Nui.
Gali, Kopaka, Pohatu, and Onua used their Kanohi Kaukau to retrive a Miru hidden underwater in BIONICLE Chronicles 1: Tale of the Toa.
- Tahu - Former secondary mask
- Gali - Former primary mask
- Lewa - Former secondary mask
- Pohatu - Former secondary mask
- Onua - Former secondary mask
- Kopaka - Former secondary mask
The Kaukau was first released in 2001 as part of the Gali set, and it was also released in the other colours of the Toa in the Kanohi Pack. Hahli from the 2001 McDonalds' set also wore a Kaukau.
- Before the Bohrok destroyed it, Naho Falls had a massive Kaukau statue carved into it.
- This mask is not related to has nothing to do with Turaga Matau's Kau Kau Staff.