Pokémon 4D: Pikachu's Ocean Adventure (ポケモン3Dアドベンチャー2 ピカチュウの海底大冒険, Pokémon 3D Adventure 2: Pikachu no Kaitei Daibōken) is a short anime film that was shown in 4D. It is the second 3D Pokémon short. The plot involves Pikachu and friends going on vacation, only to be visited by Chatot, who has found a treasure map leading to a legendary treasure known as the Wailord's Tear, which is located in a sunken pirate ship.
The film had a limited run in Japan in select theaters starting in 2006. It was later dubbed into English and premiered at the IMAX 3D Theater at Jordan's Furniture in Avon, Massachusetts. It was distributed by SimEx-Iwerks. It played there for a while, but it is no longer playing. SimEx-Iwerks claims their rights to the film have expired. It is not currently playing anywhere, and as such it is unavailable.
It was screened again in 2017 together with Pokémon 3D Adventure: Mew o Sagase! in Japanese theaters.
Some footage is publicly available, however. In addition to a teaser shown on Japanese TV, SimEx-Iwerks uploaded an English trailer to their YouTube channel and a 30-second clip to their site, which was then uploaded to YouTube by someone else.