Here are some options:
Closest Sounding:
* Zaka: This is the closest-sounding Hawaiian name, but it doesn't have the same meaning or origin.
Hawaiian Names with Similar Meanings:
* Zane: This name means "God is gracious" and has a similar sound to Zach.
* Kaimana: Meaning "oceanic", this name evokes a sense of strength and power, which could be similar to Zach's personality.
Hawaiian Nickname:
* Zaki: A shortened version of Zach, which can be used as a nickname.
Ultimately, the best way to say Zach in Hawaiian depends on your preference and the context. You can choose a name that sounds similar, has a similar meaning, or simply use a nickname.