Sea monster scare

The Scooby-Doo Readers are a level above the Picture Clue Books. The text is easy-to-read and the art is bold and full-bleed, making these an appealing Level 2 reader. Scooby-Doo and the gang are enjoying a relaxing day at the beach. Sun, sand, snacks, and sea monsters? "Ro Way!" says Scooby. But if it wasn't a sea monster, what destroyed the gang's sand castle? And where is the gang? Scooby and Shaggy have to find them fast!