Puffin The Worst Witch All at Sea.

The Worst Witch All At Sea is the fourth hilarious adventure in The Worst Witch series. Mildred Hubble is in deep water on the school trip! Lovable but disaster-prone Mildred Hubble is possibly the worst ever trainee witch to darken the doors of Miss Cackle's Academy for Witches. When the class goes for a week's school trip to the seaside, Mildred can't bear to leave behind her beloved cat, Tabby behind, so she smuggles him along. But keeping Tabby hidden leads Mildred into yet more trouble...