I created the cake for my husband's birthday - he's an avid scuba diver. It was his birthday and launch of his website.
Here's my "recipe":
Made a 3 layer cake with white frosting.
Sprayed with food coloring spray (craft store - $3).
Purchased lego scuba set on Ebay.
Purchased "reef toys toob" at craft store.
"Beach stuff" also purchased at craft store, as was confetti, candles, etc.
Sand made with combo of graham cracker crumbs and brown sugar.
Jello made separately, used 3/4 of water per recipe; waited for it to set.
Set in the diver, shark and fish.
Transferred jell-o to top of cake and "cemented it in" with frosting and a few toothpicks.