In Star Trek: Deep Space Nine, the aliens known as "the Prophets" lived in the Bajoran wormhole. You could call the wormhole "Prophet Island". Now, the Ferengi weren't worried about prophets; they were only interested in profits. So, if the Ferengi had a wormhole, it would be Profit Island. (Makes sense now, doesn't it?)
We launched from just south of the I-10 bridge in Baton Rouge (N30°26.284', W91°11.524'), but any launch will do. Once you get to Profit Island, I recommend going in from about N30°35.967', W91°17.451'. There is a small harbor-like area there and a path right at the top of the beach that leads to the main road across the island. It's a really nice (and very flat) walk across to the cache site.
If you need hints, you can use them one at a time. Each builds on the last.