I love this paper plate aquarium! Cheerios and Lattes - http://www.cheeriosandlattes.com/saturday-show-tell-9-5-5/
S is for surfer craft. Also use for 20 little surfboards standing in a row...counting practice..
Ideas bonitas para hacer en casa : cositasconmesh
Preschool Storytime Crafts: Starfish great for an Under the Sea story time!
Waffle Designs | Craft | The Mailbox - Could work to paint fish scales during ocean unit
Hand and Footprint Lobster « Animal
Bubble Wrap Sea Turtle Craft www.daniellesplace.com
Tippytoe Crafts: Blubber Experiment (show kids how blubber works - good for W week with whale project)
Paint on tin foil, use a Q-tip to wipe off paint to expose foil in patterns before it dries, then cut out a shape with construction paper and glue it on top. Very cute idea.
This site has several underwater themed activities, crafts, and games for preschoolers. Most could be adapted to include the Biblical content of Operation Overboard for our Pre-K class.