Mantine Surf is the new PokéRide style feature. Accessed in Big Wave Beach on Melemele Island, Heahea Beach on Akala Island, Ula'ula Beach on Ula'ula Island and Poni Beach on Poni Island. Each island has a longer and more obstacle filled course.
The idea here is to go between two islands doing lots of tricks along the way. To do this, you need to pick up speed by going up and down the waves, occasionally jumping up the wave to do the tricks. For each trick you do, you get an amount of points based on height and speed, and if you land properly you will get a special landing bonus. If you don't land properly, you will fall off and lose speed
There are however numerous obstacles that you'll encounter while trying to rack up speed to do tricks. These need to be navigated around in order to not lose Speed, but each obstacle has got its own special feature and their placement is random on the course.
To get points, you have to do various moves. These are initially standard with Left & Right being spins while Up & Down being a Backflip and Forward Flip. However, there are multiple other moves that can work better to get higher scores, and can even be chained if you have enough air.
Location: Heahea City
After you have defeated all the high scores in each of the four different Mantine Surf courses, you'll get recommended to go to the Surfing Association office in Heahea City. Go there and speak to the man. He tells you of how he used to be a Mantine Surfer, and then will give you a special Pikachu that knows the move Surf.