This game has the worst Swimming mechanics ever

[KING JULIEN]

How the hell do I swim down? I am holding space and I keep swimming up

[xr ඞ]

Press forward, if it's inverted. Otherwise press backward.

[Nonexistinghero]

You can't move diagonally down, only straight. If you press diagonals you'll swim up. It wasn't like this in the 360 original or Sigma 2. For some reason it's effed up in Black 2.