During the first week of autumn at Baywatch with Hobie gone away to college and heavy rainfall in the area, Mitch discovers that his shipboard marriage to Neely is invalid, which worsens things then Neely's ex-husband suddenly shows up with no knowledge of Neely's baby or anything else making Mitch realise that Neely lied to him all this time and she has fully reverted back to her conniving and devious true self.

Mitch, Craig, Neely, J.D. and Newman co-operate with the Coast Guard in rescuing as many people as possible from the waters of the plane crash and fending off shark attacks as well.

While on her way to her grandmother's birthday party, Alex's day gets sidetracked when she tries to save a diamond runner, named Ben, whose partners, Lisa and Jason, want to silence him for good which leads to a standoff in an underwater cave with Alex and Ben trying to avoid the rising tide and the smugglers circling above in their motorboat.

April tries to save Manny from himself after he suffers a life-altering back injury during a rescue. April then decides to take Manny's place with Hobie in a boat race with the other lifeguards from Baywatch.