The KanohiKaukau was the Mask of Water Breathing, sometimes abbreviated as the Mask of Water. It gave its user the power to breathe underwater, albeit only to a certain depth and for a limited amount of time.
Kanohi Kaukau were carved out of a mixture of Shrink, Regeneration and Remove PoisonKanoka on Metru Nui.
Great: During their quest to collect the various Masks of Power, Gali, Kopaka, Pohatu, and Onua used their Kanohi Kaukau to retrieve a Miru hidden underwater.
The Kaukau was first released in 2001 in transparent blue with Gali's canister set, and was also available in transparent red, green, black, white and orange as one of the two randomly-selected Kanohi in the supplementary Mask Pack.
In 2002, the Kaukau was also released in a similar Mask Pack, this time in gold or silver and also coming with three Krana in addition to the other randomly-selected Kanohi.
The transparent blue Kaukau later returned in 2003, as part of the Hahli Matoran set.
The Kaukau was released in yellow and light blue colors; however, they are extremely rare.
The Kaukau had "9-MA" as a code printed on the inside just above the axle which could be entered in the 2001 promotional CD.
Before the Bohrok destroyed it, Naho Falls had a massive Kaukau statue carved into it.