Forum:When does one arc become another?

Galaxy 9000 and I have been talking in the chat about where the line two between arcs occurs. This is difficult to distinguish for arcs such as Water 7/Enies Lobby and Amazon Lilly/Impel Down. It also affects things like manga cover stories in the anime, such as the SH Separation Serials.

I personally think the line should be when the SHs (or other important characters) arrive at the location the next arc occurs. So the Sea Train story, while no longer taking place on Water 7, should still be part of the Water 7 arc, because the SHs have not arrived at Enies Lobby yet. And the first part of the the SH Separation serial in the anime would still be part of Amazon Lily, because Luffy, Hancock, and Momonga are still shown in-transit to ID, and have not arrived yet. I believe this is the current policy we have, according to the anime episode guide.

Gal thinks just the opposite, and I can can see how he does. It is a hard definition to make, so we thought we would make a forum about it, since the consequences of a decision on this issue affects many arcs. JustSomeDude... 05:14, July 26, 2012 (UTC)

Discussion
Little bump on this forum. Where do you think episode 457 and episode 458 stand? Personally, I think they belong in the Impel Down arc, since the title of the episodes say it's before Marineford (meaning, before the war, which is the arc), and since no pirate really made it there yet. No chapters start where these episode correspond, either, so I don't think it belongs on the Marineford arc. 01:52, October 5, 2012 (UTC)

No chapters correspond in the Impel Down Arc either. It fits better in the marineford anime episodes section. 02:00, October 5, 2012 (UTC)

The content of those episodes is nearly entirely related to Marineford. Why should they not be in the Marineford arc? 02:07, October 5, 2012 (UTC)

Because the episodes specifically state that it's before Marineford. I understand that it's also unfitting for it to be on Impel Down, but part of the recap is IN Impel Down, and, like I said, it says before Marineford. 02:09, October 5, 2012 (UTC)

The episode titles are highly irrelevant. The episode content fits better into Marineford, and therefore goes there. 02:10, October 5, 2012 (UTC)

How are the episode titles irrelevant? They tell where they are in the story. And the content doesn't really fit in Marineford anymore than it does in Impel Down. It's like the Gaimon episode. It doesn't go anywhere, really. 02:16, October 5, 2012 (UTC)

Yes, without Marineford could these really stand as their own arc? All the information here is meant to be applied to the Marineford arc, so if all the content fits with the arc, why should it not be part of the arc? 02:19, October 5, 2012 (UTC)

Because the retrospectives exist to prepare you for the arc. Like we're not going through the doors yet, we're just reminding you of something. And I'm not saying it should be in its own arc. But I think it should go in Impel Down since it's gotta go in one of the two, and it has to be before Marineford. 02:24, October 5, 2012 (UTC)

Think of it like a book. Some books, specifically comics, open up with a "the story so far..." kind of thing. But the story of the book doesn't actually begin until the first chapter, which is after "the story so far...". In this case, "the story so far..." is the retrospectives. 07:32, October 7, 2012 (UTC)