To start I got out one of our sensory bins and filled it up with water, then mixed in some neon blue food coloring until I got the color I wanted. Then I added in some seashells and the contents of our Animal Planet Animal Head Tube - Sea Life tube.
My daughter played and played for a while. At first she delighted in looking at all of the sea animals. The great thing about the ones from the Animal Planet tube is that they all have the names written on their bottoms so you can work some knowledge in during play.
After a while I gave my daughter a plastic cup so she could pour the water, or collect sea animals in it.