Ok. Thanks for the additional info.
You would need to definately talk to a priest about the specifics. BUT, with that being said, you can get special exemptions. But, as someone mentioned, you need to get the Bishop's approval. You would probably need not only his (the priest's) bishop's appoval, but also the Bishop presiding over the Hawiain islands.
It's just extra paperwork and such. It took me 12 years to finally get my marriage validated in the Church. We got married Lutheran. It wasn't any big deal. They might make a stink about it because there is no overwhelming factor why you couldn't have the ceremony in the Church. It's possible that they may decide to have the official Church ceremony done before you leave in the chapel or main building.
But you are also going to have to consider the fact that this priest may not be able to get away from the Parish very easily. He would have to have backup.
Just start planning as early as possible. And don't listen to me or anyone else on the internet...except for this: Make an appointment with this particular priest if he is local. If he is not, make a phone appointment. He will tell you what procedures will have to be followed. There is a difference between what is acceptable and permissable.
You are not the 1st Catholic to want to get married on a beach in Hawaii. Good luck and congratulations!!! I wish you many, many happy years together!