If you're not a comic book reader, the notion of Namor flying may seem completely absurd. But he can, and it's a part of his genetic mutation as the Avenging Son of Atlantis and the Feathered Serpent God Kukulkan. His wings give him a lot of mobility, power, and versatility in battle, allowing him to burst forth from the water at a moment's notice. They also help him track underwater enemies.
When Namor isn't fighting crime as the Sub-Mariner, he's working for the preservation of Earth's oceans by using a fortune he earned by finding sunken treasure to buy and run Oracle, Inc., an environmental and conservationist-minded corporation. He's been known to work with and against the surface world's heroes, both as a foe and an ally, and has served on numerous superhero teams over the years, including the Invaders, both the modern-day and World War II versions of the team, and the clandestine policy group the Illuminati.
He's also fought alongside the Avengers, and both the original Human Torch and his successor, Johnny Storm. He and his wife, Lady Dorma of the Chasm people, worked for and with the X-Men, and he's even been a member of the Defenders.
While he doesn't fly in the new movie, Marvel's Craig Hammack confirmed to B&A that the character is capable of flight and that the VFX team has filmed him in action with his wings in place. They're a little hidden, thanks to some snazzy costume designs, but they're definitely there.