Ocean Clouds

Ocean Clouds (海雲, Umigumo; also Sea Clouds) are large water-like clouds. They form seas in the sky. One can sail on it if he's not too heavy to sink through it, or travel through using Waver or Jet Ski. But they are lighter than water, and as such, things that drop into it sink faster than in normal water. However, they are still affect Devil Fruit users like a regular body of water would.

Sea Clouds, as well as Island Clouds, are created when an element contained in the Kairoseki called 'pyrobloin', ejected into the air by volcanic eruptions, comes in contact with water vapor. The density of the water vapor determines whether Sea Cloud or Island Cloud will be created.

There are two known seas: the White Sea and the White White Sea.

First Appearance: Chapter 237; Episode 153

The White Sea
The White Sea (白海, Haku Kai) is the lower part of sky ocean, located 7000 meters above the Blue Sea, comprised of Sea Clouds. It also has strange, rubbery clouds that bounce objects off of them and can be used as trampolines for those who are creative. There are different ways to get to the White Sea from the Blue Sea. The only way that has been shown so far is the unorthodox and dangerous way in which the sailors have to take a Knock-Up Stream.

First Appearance: Chapter 237; Episode 153

Known locations in the White Sea:
 * Heaven's Gate
 * Clouds End

The White-White Sea
The White-White Sea (白々海, Haku Haku Kai) is the upper part of sky ocean. It is located 10,000 meters above the Blue Sea. Skypiea (among other sky islands) is located here.

First Appearance: Chapter 239; Episode 154