A teen (Chez Starbuck) learns that his birth mother is a mermaid after he begins to grow fins and slimy scales on his 13th birthday. Jess Wheatley: Justin Jon Ross. Sam: Courtnee Draper. Big John: Brent Briscoe. Sean: Tim Redwine. Whit: Dave Coulier. Sharon: Lisa Stahl Sullivan. Coach: Brian Haley.