Of all the standup paddlers doing impressive things, very few are pushing the envelope as far as Colorado’s Spencer Lacy. This titan of whitewater SUP routinely sticks Class IV rapids that would make even experienced river kayakers think twice. Not only does he charge Colorado’s fiercest rivers, but he routinely goes globetrotting in search of rapids untouched by standup paddleboards. He does exactly that in this edit from his recent trip to Chile, profiled in full in our Fall 2017 issue. Taking on rapids that seem impossible to stick, Lacy pushes the limit of what’s possible on a river.