Sea Clouds

Sea Clouds (海雲, Umigumo; also Ocean 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. Another feature that distinct Sea Clouds from normal seas is that there is no sea floor. However, they still affect Devil Fruit users like a regular body of water would. These clouds form two known seas: the White Sea and the White White Sea. These clouds first appeared in Chapter 237 and Episode 153.

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.

Fanciful creatures inhabit these clouds. In order to adapt themselves to weaker than in regular sea buoyant force they became lighter: some became flat and some became like balloons.

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 Cloud. 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. Another way, mentioned by Gan Fall is the High West, as well as a couple of unnamed islands. However, these routes are apparently very treacherous, as Gan Fall states that, "If you had brought 100 people, it would be a gamble as to how many would survive." . The section first appeared in Chapter 237 and 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. This section first appeared in Chapter 239 and Episode 154.