- Use a very long seedless watermelon for the submarine body, and a smaller seedless watermelon for the conning tower, the periscope and the rudder on the back of the submarine.
- Cut approximately 3/8 inch off the bottom of the entire length of the long watermelon so the base will appear as a submarine sitting in water, as shown in the photograph. Cut at a very slight angle so the front will appear sitting a little higher in the water than the back.
- Cut the top of the watermelon, at a slight angle so that the front of the submarine will appear slightly larger than the back.
- Scoop out the flesh with an ice cream scoop or a large spoon, and reserve for salad.
- Draw the conning tower sections on curved rind from second watermelon using a sharp pencil or thin marker. Trim as necessary to make the two pieces fit together to form the tower. Cut slits on the side of the tower as shown and insert side pieces. Connect to top of submarine with toothpicks.
- Draw the rudder on the flat rind from the second watermelon. Trim as necessary to make the two pieces fit together to form the rudder. Cut slits on the side of the rudder as shown and insert side pieces. Connect to submarine using toothpicks.
- Draw periscope sections on the flat rind from the second watermelon. Pierce with a toothpick to make the handle, as shown, and cut off sharp ends of toothpicks. Insert into the tower as shown.
- Place on platter with blueberries all around to appear as water. Fill sub with fruit salad that has been cut with a French-fry style crinkle cutter, as shown.
- Replace top and decorate with toy captain and inverted swizzle sticks to appear like antennas.