My boat is similar to yours, but I only have a large fishbox that extends to under the chair - as opposed to a separate area for storage. I took the time to look at an old brochure to get a better idea of the area since there wasn't a picture here - it was the brochure that mentioned tackle boxes.
Does the carpet get wet from the top down? You can figure that out easy enough, but using a hose is still a good idea to figure this out for sure. You don't have to pull the carpet for that.
EDIT: Oh, just a quick add... most of these walk around style boats are built pretty much the same. So if you get recommendations from others that have different (but similar style) boats, don't discount their help. Actually, you could very well get good advice from someone that doesn't have a similar style at all. Many on here are very familiar with boats, in general, and can still offer good advice even if they don't have a similar boat.