This "any card at any number" plot is almost too perfect:
A deck of cards is handed to a spectator. A card is named, along with any position.
Without manipulating the deck, the magician takes the deck, counts to the named position. Not only is the named card at the chosen position, but after that there are two kickers that no other routine allows: on the following card it is written that exactly this position will be named. But this is not enough! Show the game to show that no other card was present in the game!
OCEAN stands for Only Card Exactly At Number, an ingenious idea by Las Vegas mentalist Colin McLeod, who has built three highlights into a single effect.