I'm aware of the basic value in wet-sanding and actually worked for a couple of years hand-wet-sanding sculptures for an artist back when I was in college. Wet-sanding between paint coats is faster than dry sanding, but not faster than not sanding between coats at all and using something like a scotchbrite pad instead to prep for the next coat. When you then apply the next coat, the value of your we-sanding effort goes right down the drain. All you need to do between coats is to knock the gloss down and smooth out any glaring irregular spots. Get all of your paint on and actually let it cure to a more final state before you get out the wet-sanding paper if your intention is a smoother finish.
The green boat had no sanding (a quick rub-down with scotchbrite only) between coats, and no sanding after painting. I painted it out in my driveway, roll-and-tip with Brightside enamel. At the time of this photo, the paint job had been sitting outside, uncovered for three years and it was in getting cleaned up after sitting on a mooring for the previous summer.
If I'm going to bother wet-sanding a paint job, I'll wait 7-10 days for all the paint to cure properly and finish shrinking. Then, and only then, will I start sanding it. When I'm done, I expect it to look like this. Again done with no wet-sanding between coats. All sanding was done after cure and final buffing was done by hand with a cotton cloth.
I don't generally wet-sand boats, because frankly, it's a boat not a piano (or guitar) - but if you choose to do so, fine - but why not save it for a point in the process where it can actually do some good.
