I think you have 2 problems. The first is water damage, and the 2nd - depending on the type of finish, could be loss of finish.
I'd try the following in this sequence:
1) Heat the finish with a blow dryer.
Use a medium setting and don't stay in one place too long. The heat can cause moisture to evaporate. Avoid getting the finish any hotter than is comfortable to touch.
2) Apply an oily substance, such as petroleum jelly or mayonnaise,to the damaged area and allow it to remain overnight. The oil will often restore some of the transparency by displacing the water (oil being lighter than water).
3) Assuming the finish hasn't been removed, cut through the damage by rubbing with a mild abrasive such as toothpaste, or with salt mixed with olive oi, or use a plastic kitchen 'scrubby' lubricated with a light oil, such as mineral oil. Rub the damaged area until the water damage is gone, being careful not to rub through the finish. Then, if the sheen is different from the surrounding area, you can 'even it up' by rubbing the entire surface with paste wax.
4) As a last result ONLY: Dampen a T shirt type cloth with some denatured alcohol (not rubbing alcohol). Dampen, not wet. Then using a motion of a plane landing and then taking off again, go over a small area. Try this a number of times. Let us know the result
Bob "Boardman" Borders