This is the cake I made for my twins' 4th birthday.
9x13 sheet cake
graham cracker crumbs
Fruit Stripe gum
Fruit by the Foot gummies
gummy rings and fish
Frost cooled sheet cake with blue frosting. Add an island of graham cracker crumbs. For the palm trees, stick a pretzel rod into the island and add leaves made by rolling out green gumdrops and cut into leaf shapes. Add "rocks" to the edges of the island.
Use the decorating frosting to add sunglasses and swimsuits on the Teddy Graham bears. Put them on Fruit Stripe gum towels or gummy ring floats or Fruit by the Foot air mattresses. Add gummy fish and sharks.