When I say "expert", I don't mean intellectually or professionally so much. I mean an informative person that can give great advice to someone who is looking for information on a particular topic.
And you can become that "expert" by doing your research and adding as much info about the Caribbean that you want. So it's definitely something you can research as you go.
This should be fun and not feel like work so don't think there's THE perfect way of going about it. It's all about finding something that interests you and presenting the information in the most useful, informative (and even entertaining) way possible.
Look at Ken's daughter's site
www.anguilla-beaches.com. It's written from a teenager's point of view and they are based on her experiences on the island of Anguilla. Notice the personal photos, restaurant reviews, etc. Everything is very casual.
No one's going to ask you or expect you to have official credentials if you're simply providing advice based on your experience. And if you want to add information on your site from your own research then you should site your references letting your audience know where you retrieved the info from.
But if the information you put on your site is common knowledge and written in your own words, based on your own experiences, that's all you have to be concerned with.
Think of building your site as a person helping a friend learn about the Caribbean. What restaurants would you recommend? What sites would you recommend seeing? Can you show pictures from your travels that will appeal to your audience? These are the kinds of things you want to think about.
anguilla-beaches.com is a great example of how to build a content rich money making site without it looking like a money making site, if that makes sense.