Sneak box. our sneak box is an updated and improved rendition of the barnegat bay sneak box. the most important difference in our version is the inexpensive materials. Welcome to absolutely free plans, in this section you will find free boat building plans including accessories and construction techniques. free plans have a tendency. Free rowing boat plans for the backyard home builder, build your own rowing boat, dory, folding dinghy or pram using these simple plywood designs..