Where to find Wooper in Diamond, Pearl & Platinum

Surf: Great Marsh (90%), Sinnoh Route 212 (90%, Only in Diamond & Pearl)
Walk: Great Marsh (70%, Great Marsh rotation, Before the National Dex), Sinnoh Route 212 (25%, Only in Diamond & Pearl)

• Great Marsh (1) — Surf, Walk
• Route 212 — Surf, Walk

Wooper in every game · Pokémon Diamond, Pearl & Platinum interactive map (Sinnoh)