Alright, there's some tricks to it that'll help you attain high scores consistently. The max amount of BP you can get is 50, and while I haven't attained it yet, I know just how it's possible to do it (my maximum is 40BP):
1. Always start from Ula'Ula. Melemele and Akala are both too short, and Poni contains too many obstacles.
2. Don't leap out of the water until you glow red, so build up speed first while avoiding the obstacles. The farther out of the wave you go, the more speed you build up, but don't go too far out as to lose it all.
3. This is the important part. Don't spam button inputs during aerials. When you come out of the water, wait for Mantine to glow, and execute your first input. After every input, you'll notice a circle start closing around Mantine. As soon as that circle closes and Mantine glows, make your next input. That way you can max out points gained during aerials.
4. With this in mind, Lanturn on high waves, and Primarina on low waves. Use Starmie when coming down. When you're doing Starmie, the circle will close much faster, this is to prevent you from wiping out.
5. Magikarp Splash and Over-the-Gyarados should both be used once, so try and combine them to create a spectacle. When you think you're ready to perform OtG, do a Magikarp Splash first, then Huntail/Gorebyss Spiral on the way down. On the next jump, perform Over-the-Gyarados, and come down with a Huntail/Gorebyss Spiral to get around 14k points.
Keep repeating these steps, and you'll be smashing records in no time.
