Collins Big Cat is a guided reading series for ages 4--9 edited by Cliff Moon.

Top children's authors and illustrators have created fiction and non-fiction books that your children will love to read, banded to help you choose the right book for every child.

Practical teaching notes are included at the back of each book.

What is going on under the ocean? A whole other world is living there -- but it is becoming a world in danger.

Find out about the ocean world and what threatens it in this non-fiction book.