But one clip shows Nick, played by British actor Frank Dillane, underwater and about to be attacked by a zombie on the surface.
"Zombies can't swim. They can wade but they sink," showrunner Dave Erickson told the audience at Hollywood's Dolby Theatre.
"So it was actually something we experimented with when we shot the first episode, with varying degrees of success.
"But we've figured out the best ways to shoot water zombies. They don't drown. They keep floating back up."
The first season of Fear the Walking Dead, which was filmed in Los Angeles and Vancouver on Canada's west coast, debuted in August last year.
More from Spy:
• Breakfast stars reunite on radio
• DWTS star turned wedding singer?
Over six episodes it went on to become the highest-rated first season of any series in cable history, with an average of 11.2 million viewers.
Production moved to Baja California, in Mexico, for the second season, which kicks off an extended 15-episode run on April 10 on AMC.
-AAP