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In Anime/Manga One piece, when straw hat pirate had finished explore the entire island ( or beat the bad guys ), straw hat pirate will continue their journey to the next adventure ( a.k.a next island ). They travel around grand line using Going Merry soon will be replaced with Thousand sunny. The manga/anime never mention how long they have been in sea ( cause using a boat to travel in sea would be take a month maybe a year ). In anime/manga it's like the distance between previous island and the next island only take an hours to make it. Is the distance of island in one piece not really that far ?