Ideal for elementary learners of English looking to improve or practise their English. The book is filled with useful vocabulary that is carefully graded and easy to understand, it also comes with audio, so that you can listen to the story at the same time as reading. When Tonya and her friends decide to sail around the world they want to see exciting things and visit exciting places.But one day, they meet an orca - a killer whale - one of the most dangerous animals in the sea. And life gets a little too exciting.