[FRPLG]

Actually I think the proper way to think about it is that time for the islanders and the boaters was tracking properly. It was time for the copter passenegrs that was screwy. We know this because when they landed the time on the boat seemed to match the time on the island. We know this because they took off at dusk and landed in the middle of the day so they essentially flew for almost a day but in only twenty minutes.

Yet another way to look at it is that time on the island and time on the boat are out of sink in some way. So when they took off form the island at dusk they were actually leaving at a different time than it was on the boat.

I suspect the former though.

I am guesing that whatever electromagnetic properties Faraday utilized on Eloise take place naturally in around the island and the only way to avoid the affects is to travel a specific route that avoids the frequencies at which the phenomenom happen.