Big Duel in the Blue Waters (蒼海の大決闘 Sōkai no Daikettō) is the fifth Extra Pack for the Z/X -Zillions of enemy X- TCG.
- The set's tagline is "It's summer! It's Z/X! It's Ignition!!" (夏だ！ゼクスだ！イグニッションだ！！)
- Not to be confused with the April Fools' Extra Pack, which also uses the same art piece and tagline.
- Similar to the first Extra Pack, this set only contains Rare or higher rarity cards.
- Includes reprints of popular Rare cards from "Booster 1: Encounter with the Parallel Worlds" to "Booster 6: Maiden of the Five Dragon Gods" with two reprints for each color. All reprints also comes with new illustrations.
Each packs contain 4 cards and each boxes contain 10 packs. There are 30 cards in total (20 new cards and 10 reprints) + 30 holographic cards, excluding special cards.
- Rare: 25
- Super Rare: 5
- Hologram Rare: 30 (holographic version of all Rare and Super Rare)
- Each sealed packs comes with a Z/X Point.
- Each boxes comes with 5 card sleeves (initial production only).
- Official Product Page (Japanese)