If cake top is rounded, trim horizontally with long serrated knife. Trim sides of cake. Place cake on prepared cake board.

Tint Creamy White Frosting blue by adding small amount of desired paste color with toothpick; stir well. Slowly add more color until frosting is desired shade.

Frost top and sides of cake with Base Frosting to seal in crumbs. Frost again with blue frosting. Swirl frosting to resemble waves.

To make large fish, position 1 large gumdrop on cutting board and cut lengthwise in half. Set aside 1 gumdrop half for fish body. For tail, place remaining gumdrop half, cut side down, on cutting board. Cut wedge piece from center of wide end. Place fish body in desired position on cake top. Place narrow end of tail piece next to wide end of fish body. Trim reserved wedge piece into fin shape and place above body of fish.

For eyes and bubbles, cut off small pieces of gumdrop and press onto fish and cake. Decorate fish by cutting additional small pieces of gumdrop and pressing pieces onto fish, if desired. Repeat with additional large gumdrops to make more large fish. Repeat with small gumdrops to make small fish.

Beat shortening in large bowl with electric mixer at medium speed until fluffy. Gradually beat in 3 cups sugar until well blended and smooth. Carefully beat in 3 tablespoons milk and vanilla. Gradually beat in remaining 3 cups sugar, adding more milk, 1 teaspoon at a time, as needed for good spreading consistency. Store in refrigerator.

Combine sugar, shortening, 1/4 cup milk and vanilla in large bowl. Beat with electric mixer on medium speed until smooth. Add more milk, 1 teaspoon at a time, until frosting is a thin consistency. Use frosting immediately.