What's the ups and downs to painting the bottom of a boat with paint? Not bottom coat. Saw a boat with white paint on the bottom and didn't think that was a good idea over just sanding and buffing the gel coat.

From what I hear, if you have bottom paint the boat needs to stay in the water.

My hull bottom was painted with white epoxy about 10 years ago. It is extremely difficult to tell the difference in color from the gel to the paint. The bottom is also easier to clean as the paint is not as porous as the gel.
ed

I have scrubbed many a boat bottom with the white epoxy applied and can tell you it works well . Easy to clean and no boat pox .

Only downside that I can think of is that the boat should not be left in the water for long periods of time(5+ days) The paint can get blisters.

Mine has been in the water all summer for the past 5 years and it is blister free. I would think the blister issue is a gel related. There is no rack storage around my area and I've spent way to many years hauling boats and trailers around.
ed

I agree Ed , the epoxy does a very good job of sealing out moisture . If applied right is smooth as your jell with no noticeable loss in speed .

I agree somewhat. It really depends on what paint is used. Some paints will blister easier than others.
My drive lowers were painted with Awlgrip and they have some blistering from being left in the water for 7-10 days.