Hi David,
I'm not even sure about the poor quality of some of those boats. As a demonstration, a group of Pacific Islanders built seven vakas and set out from Auckland, New Zealand this April. They sailed to Hawaii, predominantly using traditional navigation techniques. Then they sailed to San Francisco, and currently (8/20/11) they're sailing south off Venice Beach. They'll end in the Solomon Islands next July. That's crossing the Pacific twice in 18 months. Not too shabby.
Here's
The Vaka Moana website, which chronicles their voyage.
While traveling through the modern Pacific is a great deal easier than it was 1000 years ago, I think we under-rate both Polynesian boats and sailing skills. Even finding unknown islands isn't a blind shot: when you see land birds take off into the open ocean, you know they're heading for other land somewhere. That's how the existence of New Zealand (and Hawaii) was inferred.
Best,
F