Finally got to the diner.
Heres a hint for everyone else that I found on a site.
First, Build horizontal speed. After 20 nice-entries, shoot straight up perpindicular to the water and starslide 3-4 times, then do one tailslide horizontally, When you shoot up do not tail slide past neptune, you wont have enough time to come back for the final jump. when you land in the water again perform one last tailslide and hit every starslide you can, you should get to the diner.
Heres. where I found this.
http://how-to-kongregate.blogspot.com/2007/12/dolphin-olympics-2.html