Water does ×1 to Dark

Generations VI to IX, single types. The other way round, Dark against Water, is ×1.

154 Water and 69 Dark species among the 1025 this site covers.

Attacker, Water Kyogre sprite

Kyogre #0382

damage×1Generations VI to IX

Defender, Dark Umbreon sprite

Umbreon #0197

Dark did not exist in Generation I, so Water against Dark has no value there.

Strongest Water attackers

Kyogre leads Water at Sp. Atk 150

Sturdiest Dark defenders

Dual types that change the answer