There are several very nice skiffs in Edwin Monk's book How to Build Wooden Boats. But it was published in 1934 so the plans are for plank construction with a table of offsets.
For the 15' boat that I built I used the offset table to frame up a back bone out of cheap plywood. Then I laid cheap luan plywood on the back bone and cut out patterns for plywood construction.
For a 15' boat I ended up getting all the wood I needed for the hull from 4 sheets of 3/8 marine plywood and 2 sheets of 3/4 ACX for framing. Glass over wood makes for a seriously stout (and heavy) little boat.
1988 20' Walk-Thru