incrediBILL - 10:51 pm on Jul 2, 2012 (gmt 0)
Safari will use your system languages in order of preference, even if neither the OS nor the browser itself has a user interface in the language.
While there is an entry in the ISO-639-2_utf-8.txt [loc.gov] for "haw|||Hawaiian|hawa´en", I've never ever seen it in actual usage for accept-language but someone else may have.
MS even dumped the Hawaiian font in Windows 7 that used to be in XP and now you have to get it from a 3rd party source.
I'd have a look at how apple does things:
We're talking Hawaii, think pineapple instead ;)