Red Tide.... (Unabridged‪)‬

Four kids, five creatures, and an old town drunk called Old Charlie. On an island off the eastern coast, a storm opens up a huge new cave and takes the island back millions of years when five denizens of a bygone era awaken. Sunken boats, missing people, and only a few clues are left to piece together what's happened.

No one believes the kids, no one believes Old Charlie but they have to get some one to believe them before it's to late....