From Bulbapedia, the community-driven Pokémon encyclopedia.
Diablo's Ocean (Japanese: 魔の海域 Demon's Ocean) is an anime-exclusive location in the Sinnoh region. It was featured in Cheers on Castaways Isle!.
Diablo's Ocean is an area where many ships have their instrumentation go haywire or even break due to a magnetic force being given off by meteors floating around.
The area is also home to an island, where the local Water Pokémon were gathering meteor fragments to help restore a Deoxys whose crystal landed on the island during a storm. It was then later revived after receiving help from Ash's Pikachu and Dawn's Piplup.
Pokémon seen on Diablo's Ocean
- Diablo's Ocean is probably based on the Bermuda Triangle, seeing as naval and aerial vehicles drown in this ocean. This is further enforced by the Japanese name of "Demon's Ocean", similar to the alias of the Bermuda, "Devil's Triangle".