I don't have the skill to link good sections (Start; Mid; End) together. So the author time should be beatable by the average player after a few attempts. In the beginning there is at least 0.5 to gain over my author time.
But don't get frustrated with bad starts. The most impotent part are the two wood slides. Get as much speed as possible before those and try to keep it. With that you can recover from a slow start.
Also, I don't know if it actually is possible but I think you could get enough speed to skip the water entirely. You will need more then 550 speed though.