Free black skiff plans. design black skiff. designer mark wallace. l.o.a. 14′ beam 4’4" glued lapstrake ply with sawn frames. bottom and first strake are sheathed in. A 12 ft skiff a 12′ two sheet skiff. yet another way of chopping up two sheets of plywood, to come up with a very easy-to-build, yet good looking and versatile 12 ft. Spira international wooden boat plans. following are the stock plans available for the various types of boats, separated into the different categories..