I made this OCEAN cake for my son's 7th birthday. I covered it with blue buttercream and then put a thin layer of blue piping gel over the buttercream and used an off-set spatula to make the waves. The island is crushed graham crakers crumbs and light brown sugar. All the ocean creatures are plastic so I just placed them on the cake and my son can now play with them! It was a very fun and easy cake to make.