After serious consideration and absolutely no life I have come to the conclusion that the island moves. I might even have some sound facts behind this. Allow me to explain.
The island consists of various items of interest that would suggest the island moves. I also cannot paste anything on here and have no idea how to post a pictue so you will have to use your imagination.
1. The Black Rock: The black rock is no doubtedly an ancient slave shift more than likele transfering slaves from Africa to America. Now why would a slave ship be entering the ports of California? When slavery was still legal California was not very richly inhabited and therefore would have no reason to have a slave ship entering it's ports. So that would therefore but the island somewhere on the east coast of the united states.
But wait! It gets better!!!
2. Ecko's brother's plane. Now correct me if I am wrong but I believe that Ecko heils from Nigeria??? At any rate a country in Africa none the less. So if you are trying to fly to America in a single engine sesna you do not head straight accross the ocean. You would have to stay close to land. So you would stay accross to South America and up (I know it is cutting it close to fly to south america to africa but you would certinely not make it to America on a single tank of gas.) That woudl mean the plane crashed around south america which would put it around there.
3. Desmond. When you have a sailing race around the world you go below South America and back up.(you are not aloud across the suez canal in a small boat) That means that he ran aground somewhere between austalia and south america.(If you havent noticed by now there is a giant U shape goind on... use your imagination...)
4. The plane. The plane crashed between Australia and LA which would put it south of Hawaii. That would put the island where it is now.
So in conclusion I think that the island started in the Atlantic, went was south below south america (maybe picking up some polar bears if it got close enough to antartica

) and made it's way up to it's current location... Either that or I am putting way too much into this and need to take a nap... whattaya think????