1Heat oven to 350°F (325°F for dark or nonstick pans). Grease bottom and sides of 13x9-inch pan or spray with baking spray with flour. Make and bake cake mix as directed on box for 13x9-inch pan. Cool 10 minutes; remove from pan to cooling rack. Cool completely, about 1 hour. Refrigerate or freeze cake about 1 hour or until firm.
2Cut cake as shown in diagram. Arrange pieces to form sailboat on tray. Tint 1 1/3 cups frosting with yellow or brown food color for hull. Spread a thin layer of white frosting over top and sides of sails, and a thin layer of tinted frosting over top and sides of hull, to seal in crumbs. Refrigerate or freeze cake 30 to 60 minutes to set frosting.
3Frost entire cake with remaining frosting. Cut licorice pieces to desired length for the mast; place near the edge of the longest sail. To create the top flag, spread a thin layer of frosting on a small piece of aluminum foil. Unroll and remove wrapper from fruit snack roll; press onto frosting-coated foil. Using kitchen scissors, cut into flag shape. Secure flag to mast with a small amount of frosting. Use candy for portholes, or decorate as desired. Store loosely covered.