Sky Geography

Structural lore — what Oda has confirmed about this. Mysteries (unsolved questions) live in Vault/Threads/; this is what the world IS.

What we know

The first on-page systematic description of the sky’s vertical structure, per Ganfor (p.3):

• Ch. 238: Blue Sea — the ordinary ocean, below the clouds, where “Blue Sea people” live.
• Ch. 238: White Sea — a cloud sea floating 23,000 ft above the Blue Sea. Most Blue Sea people can’t tolerate these altitudes (thin air, pp.2–3). See White Sea.
• Ch. 238: White-White Sea / upper stratum — 33,000 ft above the Blue Sea; the location of Skypiea. See White-White Sea.

Additional rules established this chapter:

• Ch. 238: Extol is sky currency (pp.4, 7, 15).
• Ch. 238: Cloud-as-land — “island clouds” are soft but load-bearing; the crew bounce and walk on one (pp.11–13). The physical basis for cloud terrain in the arc.
• Ch. 238: Sky-fish guerrillas prey on crews unfamiliar with “sky fighting”; victims become “food for the sky fish” (p.4).
• Ch. 238: Heaven’s Gate is the formal entry point to the upper stratum; the Lobster Express is the transit creature that lifts ships up the cloud-waterfall (pp.16–17).

Chronology / structure

Vertical map (low → high):

Blue Sea (ordinary ocean, below clouds)
      ↑ Knock Up Stream / cloud breach
White Sea ............ 23,000 ft  (lower cloud sea; Lobster Express; sky-fish guerrillas)
      ↑ Heaven's Gate (toll: 1 billion extols/person) + Lobster Express ascent
White-White Sea / upper stratum ... 33,000 ft  (= Godland Skypiea)

Cross-links

• Characters connected: Gan Fall (delivers the geography lecture), Amazon
• Foreshadowing seeds about this topic: Skypiea Sky-Fish Guerrillas Standing-Menace Seed, Godland Skypiea Render Heavenly Judgment Seed
• Predictions that depend on this lore: