Airpower is not effectively threatened by most foreign navies unless we choose to attack those same ships. Airpower provides the asymmetrical advantage to further US interests. Our nation's interest in waterways really lies with sea lines of communication, commercial shipping in reality. This interest is tied to our value of open trade and commerce, so waterways and ports are important to our nation. Here again, the asymmetry of airpower provides great advantage.
Ships easily standout on the surface.
They must stand boldly out on top of the water. Under way, they leave telltale wakes which extend for several ship lengths behind them making them even easier to spot with the naked eye or satellite sensors. Advanced electro-optical and signal analysis sensors make this task much quicker. Anti-ship missiles hold surface ships hostage, just like Iraqi tanks were hostages of airpower during Desert Storm. Like tanks, ships use the concept of maneuver to gain an advantage over the opponent.