I would usurp Misty as Cerulean's Gym Leader, using Dual Water Types. Which 3 Pokemon I would use however? It's impossible to choose just 3, but the ones I would choose from, given certain circumstances are: Lapras, Quagsire, Lanturn, Empoleon, Poliwrath, Kabutops, Crawdaunt, Kingdra and Slowbro.