Back in the 90s, Disney Channel had new original movies released every single month. In May of 1999, that original movie was The Thirteenth Year.
“The Thirteenth Year” was directed by Duwayne Dunham and starred Chez Starbuck as Cody, Justin Jon Ross as Jess Wheatley, Courtnee Draper as Sam. Brent Briscoe as Big John Wheatley, Tim Redwine as Sean Marshall, Dave Couiler as Whit Griffin, Lisa Stahl as Sharon Griffin, and Stephanie Chantel Durelli as the Mermaid/Cody’s Mom.
Since The Thirteenth Year is a Disney Channel Original Movie it is rated G.
The movie opens when an ambitious fisherman named Big Jessie mistakes a mermaid for a large fish. As he’s hunting her down, using sonar technology, the mermaid places her newborn son in a small boat for safekeeping.
The mermaid goes back to Big Jessie’s boat and reveals herself to him. He’s in a state of shock and wonder.
Minutes later, the Griffin’s hears a baby crying and find the little boy on their boat. They name him Cody.
13 years later Cody is the most popular guy at his middle school and is the Captain of the swim team, the Marlons. He also has a beautiful girlfriend, Sam.
At Cody’s 13th birthday party, he invites the school nerd Jess to his birthday party. Sean makes rude remarks to Jess, about how he can’t swim, so Jess gives his birthday gift to Cody’s Mom and asks her to give it to him.
Shortly after a humiliated Jess leaves the party, Cody goes inside the house to get some water. Sam follows behind him and gives him his birthday gift: A frame with her picture in it and a kiss.
After the party, Cody’s adoptive parents tell him, now that he’s thirteen years old, his whole life is different. His Dad notices, the unopened gift from Jess and tosses it to him. Cody is at first, unimpressed that Jess gave him a copy of “20,000 Leagues under the Sea” by Jules Verne for his birthday. Cody isn’t a reader, he’s an athlete.
A few days after his birthday, Cody begins to feel ‘strange’. He needs to drink an excessive amount of water, his hands become sticky or slimy (like Spider-Man), he has an electric charge (like an eel), his speed in the water increases, and he has a weird scaly rash.
Not knowing where to turn, Cody confides in Jess about his fishy-like symptoms, knowing that Jess is very knowledgeable about marine biology and oceanography. Jess begins to run tests and comes to the conclusion that Cody is a merman.
When Jess tells Cody his theory, at first Cody is turned off by it, believing Jess made a mistake or has no idea, what he’s talking about. Seconds later, Cody tells Jess that he’s adopted and that he doesn’t know where he came from.
That night, Cody’s adoptive parent’s tell him how they found him in the sea. He shows them the scales on his hands and at first, his parents think nothing of it and even call the doctor. The doctor diagnoses him with puberty. But Cody, insists thats not the issue, and the changes are something else.
Cody begins to have dreams that he’s swimming under water and he doesn’t have to hold his breath. He sees a beautiful woman, luring him close with her glowing hands. The dream becomes repetitive and Cody comes the conclusion, that Jess’ merman theory is correct.
His adoptive parents finally believe that Cody’s becoming a merman, but don’t know how to help him. Cody becomes secretive around his friends, except for Jess and Sam is upset that Cody is pulling away from her. She begins to wonder, what is wrong with him and why he’s not being honest with her.
Meanwhile, Big Jessie notices the changes that Cody is experiencing and wonders if he’s connected to the mermaid he almost caught 13 years ago.Big Jess takes it upon himself to hunt the mermaid again, knowing she’ll surface again, to see her son, Cody.
Cody tries to continue normal life, despite becoming a merman and Sam discovers the truth, during nationals. Cody is forced to tell Sam the truth and learns that Big Jess is on the hunt for Cody and his mom, to prove that mermaids exist.
As Cody’s body progressively becomes more merman in the water, he realizes that to complete the transformation, he must see his mother in the sea. He goes into the water, despite his adoptive-parent’s wishes and is captured by Big Jess.
Jess, goes into the water and rescues Cody, despite the fact, that he can’t swim. Cody rescues Jess and Big Jess feels guilty for his actions and lets Cody go. Cody sees his real mother ascend from the water, calling him home. He jumps into the water, his mother’s hands glowing, and his transformation is complete.
Cody surfaces a merman. Sam tells him not to fall for any mermaids while he’s in the sea. Cody promises that he’ll return home at the end of the summer.
Cody leaps from the water and starts his new life as a merman.