Because of a Delta screwup in the fall, my girlfriend and I have $600 travel vouchers good for anywhere Delta flies, and right now it's looking like Kauai during April or May is looking like the coolest way of using these vouchers. While I strongly suspect hiking, beach-lounging, and trying to learn how to surf will be our primary occupations if we decide to go, I'd love to know the possibility of catching some fish while we're there. What are the options, based on the following points?

--Probably not willing to pay for it. I have done a little research and found there are some bonefish guides on Kauai (though Oahu seems to be better), but I can't afford such a trip and Jade isn't good enough at fly fishing yet for it, so a guided trip is probably out of the question unless I can arrange to trade a Yellowstone trip for it.
--Not interested in trout or black bass -->I can catch more and bigger of either here on the mainland.
--Given the above conditions, I don't care what I catch, though given reasonable prospects I'd rather fish saltwater, on foot.

I'd love some suggested resources (web, book) to look into, as well as some suggested flies/tackle. Figure on bringing a breakdown 8 weight and maybe a 6, along with wading sandals, tools, and a couple boxes of flies.