Boy, don't I feel foolish! I gave my brother-in-law a call and while talking to him I re-read the original post and realized I completely missed the very first part about being from Australia. Needless to say, he got a good laugh at my expense. VERY long day yesterday. My apologies.
The comments are correct about the PVSA not allowing a foreign national going from Honolulu to Seattle in this situation. If it were on different ships, you could do it, but it's the B2B part on the same ship that causes the problems.
As was suggested, you might just want to take a shuttle up to San Diego and try another cruise. Or perhaps rent a car and drive up the coast. It's an amazing drive. Or you could take the train, which is very popular.
But back to the PVSA, it was enacted in 1886 and is totally outdated. The one thing that really gets me is that CLIA (the Cruise Lines International Association) is not endorsing, supporting, or advocating any modifications to the act. Personally, I think amending it would benefit not only U.S. commerce, but would make it easier for foreign nationals, who spend alot of money in the U.S. And after all, in today's economy, shouldn't we do everything we can to encourage people spending money in the U.S.?