In 2d with no background it was alright just seeing a blue circle underneath the pokemon but it's going to look really weird now...I wonder how they'll make it look graphically. Maybe your pokemon will be swimming? That'd be awesome!
Pokemon Black FC: 4470 0364 4689 "Have you actually seen the scene in question? It needs some crackers to go with its cheese." - Poppadop
I honestly hope that it looks like they're swimming. I would love that. And I hope Dive and Dig look different depending on whether you're on land, or in water, too. On land, Dive summons a pool of water under the Pokémon that they sink into, almost like a portal, in a way. In water, Dig summons a bunch of rocks that surround the Pokémon like a tiny, one-Pokémon island, and they dig into it. During the attack on the next turn, Dive on land moves the water puddle over to the opponent, and they burst out of it, and likewise with Dig on water. The tiny group of land moves over to the opponent and they burst out from under the dirt.
Aside from that, Dive and Dig would look normal in their native areas. In water, Dive would make a Pokémon simply dive underwater, and maybe you see a faint shilouette of them swimming around underwater before they strike on the next turn.