Thresher by Michael Cole

In the aftermath of a hurricane, a series of strange events plague the coastal waters off Florida. People go into the water and never return. Corpses of killer whales drift ashore, ravaged from enormous bite marks. A fishing trawler is found adrift, with a mysterious gash in its hull. Transferred to the coastal town of Merit, police officer Leonard Riker uncovers the horrible reality of an enormous Thresher shark lurking off the coast. Forty feet in length, it has taken a territorial claim to the waters near the town harbor. Armed with three-inch teeth, a scythe-like caudal fin, and unmatched aggression, the beast seeks to kill anything sharing the waters.

Megalodon: Bloodbath by Michael Cole

A series of bizarre occurrences suddenly plague the island of Cielo Nublado. A dead whale washes ashore riddled with enormous bite marks. A fishing charter is reported missing, jet skiers vanish, and a yacht is found mysteriously ravaged after some kind of enormous impact. Chief of Police Nico Medrano tries to investigate the matter. His search for answers puts him on a collision course with an eighty-foot predator, long thought extinct. Violent and merciless, it has risen to the surface, and seeks to wreak havoc on the small island community. Things only get worse for Nico after he discovers that a ruthless band of criminals, responsible for the deaths of two Miami cops, are lurking on the island. As the body count mounts, Nico is forced to simultaneously battle two separate monsters: Man and Meg. The result is a bloodbath.