So I was just kicking back reading a few Arlong Park threads, when I came across a thread that talked about the entrence to the Grand Line. Now, I don't have a picture of it, but I assume you all remember reverse mountain. The mountain on the red line that connects all four oceans (North blue, east blue etc.) with an uphill current for each ocean that leads to a downhill current that takes you to the Grand Line.
Now, sorry I don't have any pictures, try to imagine the four oceans, north and east blue at the top, the Grand Line as a horizontal line cutting between them, and then west and south blue at the bottom. East and South blue are to the right, and between them is the starting point of the grand line. That means that on the other side of reverse mountain is North and west blue. Between those two seas is the end of the Grand Line: Raftel.
Remember when Garp, Coby and Helmeppo visited Luffy at Water 7 and Coby told Luffy about the self propelling boat with kuroseki on the bottom that allowed the marines to cross the calm belt from east blue into the grand line?
So, the same could work with somebody in north blue. If a marine in north blue had that boat, he could travel through the calm belt south into the end of the grand line. This means that the marines could and probably are already in Raftel. Since they're already on Raftel, they would have confiscated the treasure, but since we've been following along with the marine's story, they have not. There is no treasure on Raftel.
Thank you for reading.
Discuss.