The balloon will accelerate upstream.
This is College Physics Answers with Shaun Dychko. This balloon is floating on the water so that means there is a buoyant force upwards of equal magnitude to the gravity downwards. There is a current moving to the right and it's applying a force due to the current of nine Newtons and we're told that the wind or the air is blowing in the opposite direction to the current with a force of 13 Newtons. Now, since the air is exerting a force greater than the current, there's going to be a net force in the direction of the air which is upstream and so this balloon will accelerate upstream.