Invite the children to bring in mementos from their own trip to the ocean. Seashells, starfish, containers of sand, and pails and shovels are just some of the items they'll enjoy toting to school for an ocean-themed show-and-tell session. Ask parents to send in photographs and home movies of family trips to the ocean. Let the children who've been to the beach share their experiences aloud in front of the class, and invite those who've never been to ask questions.
Preschool kids take great delight in hands-on craft activities. Plan one or two projects centered on your ocean theme. Have children make paper plate fish to hang on the classroom wall. Simply cut a wedge out of each paper plate to form the fish's mouth, attach the wedge to the other side of the fish as a tail, and let the children color and decorate their "fish" as they desire. Present a lesson on the undersea animal life found in the ocean. Provide a variety of colors of modeling clay and allow children to create their own marine life afterward. Allow the clay to harden, and create a classroom display of their finished projects.
Install a saltwater aquarium in the classroom. Set your aquarium up in the evening after your students have gone home for the day, and wow them with colorful tropical fish when they come in the next morning. Alternatively, allow them to assist you with your aquarium preparations, and let them witness what you do each step of the way. Build the excitement as you work, until, at last, you introduce the fish to their new home.
Preschool kids will be thrilled with a classroom party that involves ocean-themed treats. Tie all of your lessons together on the final day with the festivities. Prepare and bring in blue gelatin dotted with gummy fish. Prepare your dish in a clear, glass bowl to simulate the look of the ocean, or fill individual clear, plastic cups with the same, so each child has his own serving. Bring in goldfish crackers, and serve an octopus made out of a marshmallow and puffed rice cereal mixture colored with green food coloring.