Decorate cake. Assemble cake layers. Using spatula and blue icing, ice cake smooth.
Helpful Hint: To better smooth cake, cut piece of acetate 1 ½ in. x 12 in. Place cake on turntable and use acetate to smooth and remove excess icing.
Let icing crust, about 20 minutes.
Prepare decorating bag with tip 3 and piping gel. Cut continents apart and place under piece of waxed paper; trace over design with piping gel. Carefully press transfers onto cake.
Prepare decorating bag with tip 6 and green icing. Using outline of piping gel, pipe in land masses, smooth with spatula.