When you pick a run in world, explore, or tour you pick your character and a screen will come up showing your gear. At the bottom left of the screen it will show your survival probability, you see that you know your on the right screen. You scroll down to your board and press the A button. It will show you four boards you can buy. Buy one and the achievement is yours. If you don't like the four boards they give you just back up to main menu and start again you will have a new set of boards to buy, you might even have a mystery buy option.