Scuba Diving Birthday Cake

I made this cake for my husband's birthday.  His favorite hobby is scuba diving, so that's what I went with.  He requesting a Dark Chocolate Fudge Cake with Chocolate Peppermint Ganache.  It was a 3 layer 10 inch cake.  I iced it in Classic Buttercream Frosting.  I dyed piping gel blue and put it on top to create the water-like look.  All decorations are made of gum paste/fondant.  I used the air brush food coloring to color the diver and the shark.  The sand is crushed graham crackers.