On Hawayy Island, you can join a surfing competition; however, first you need to buy some shorts. These can be purchased from Enzo, just outside the T-shirt shop. Change into them in the beach changing room and then join the competition. You can surf as many times as you want. To do a 540 degree turn, you need to build up your speed meter by doing small tricks. With enough speed, you will start to jump higher making it possible to complete larger tricks.
See the video below for more information.