I would honestly remove Brine.
Of course, you can't replace Surf 'cos its an HM, and Acrobatics is absolutely miraculous when not holding an item, so it was between Scald and Brine for me.
Yes, Brine has the potential to be very powerful, but only after the opponent reaches half-HP. A Pokempn could easily be vanquished with Scald or Acrobatics when it has about half HP, and also Scald has the additional burning.
As well, you also have Surf, which is pretty powerful anyway, so I think you should remove Brine.
Hope I helped. :)
Source: http://www.serebii.net/attackdex-bw/brine.shtml