Hint :
Hydro Jump:
To do the Hydro Jump you must have some boost power. To do it brake and then really fast do your booster then the boat will jump up into the air!

9 second boost:
At the start of the race, between countdown from 3 to 2 rev your boat up about halfway, then let go to let it go back down. When it is all the way back right at 1 rev it up again and hold it until the race starts. If you did it you will start with a nine second boost. It may take some practice, but it works for all boats.