As I start an ocean theme, I thought I would share some things I do to prepare. I let the children explore sea shells. They can sort them, feel them, touch them, smell them, compare them as so much more.
I also have pictures of all sorts of ocean animals. They love learning about all kids of ocean animals and what they look like and what they do in the ocean. You can always find pictures in the internet and print them and post them around the room or in the science center.