Warp 1 Mr Sulu
AirRabbit, its only if you try to accelerate to C locally, ie relative to the local space around you. Imagine you standing still on a travellater (your local space) which is moving at 10km/hr. Relatively your speed is zero. Walk along it at 7km/hr and your speed relative to an outside observer is 17km/hr.
If you travel at say .9C relative to the local space your in (which is what Bert E meant) whilst simultaneusly compressing the space ahead and expanding it behind, it "appears" (in terms of spacetime) to be faster than C from an outside observer.
Indeed Nature has proved that quasars at the remote outer edge of the observable Universe actualy move faster than light relative to us. Relative to its own space, a quasar moves sublight, just as Earth relative to its own is moving sublight. But relative to each other it is C+ because the space between the bodys is continually expanding and the rate of space expansion increases the nearer to the edge of the Universe. For the tech-minded some outer quasars have been measured as infinitely red-shifted.