Let's be honest, in most circles the descriptor "direct-to-video" is a pretty damning one. In the case of Scooby-Doo cartoons, however, it can actually be a pretty great sign. Higher budget, typical twenty-something-minute runtime, no downsides!
The Scooby Dudes join the gang in Florida, a state famous for the sun, surf, and sand. As is tradition a monster appears, comprised of one of those three components! If you think about it, it's actually pretty lucky for these teens that it wasn't a fiery solar ogre or a gritty silica-based behemoth.