The navy is better than the air force for numerous reasons. The navy is set up to fight a war, not to just support troops. It controls the SEALS and the Marines. Also the navy has planes, which neutralizes the Air Force's main advantage. Also while the Air Force's airplanes are sitting in one place, the Navy's are on an Aircraft Carrier, which is moving around guarded by a Task Force. This makes it even harder to beat the navy. In the case of an air attack the Task Force would open up with its anti-aircraft weaponry. This consists of Phalanx CIWS anti-missile defense system which will tear through aircraft and shoot down missiles. It also has SeaRAM which are anti-aircraft missiles. Also in the case of boarders, which is highly unlikely as the navy can shoot down helicopters and blow attack boats out of the water with it guns, each ship has a detachment of marines to deal with them. Also the navy can deliver a nuclear payload with its subs.
In the case of a war, the navy would do most of the fighting. The navy is just set up in a way that allows this to happen. The marines give the navy the ability to fight on land, the warships give it the ability to fight on sea and its fighter planes allow it to fight in the air. The submarines allow them to fight underwater. The air force can only fight in the air, and has no troops that are trained to fight on the ground or at sea. This gives the navy a huge advantage over the air force. Because of these reasons the navy is better than the air force.