Popular Mechanics; Courtesy Red Paddle Co. Standup paddleboards (SUPs) make a day out on the water fun and accessible to anyone with a sense a balance and a thirst for adventure. This type of watercraft is great for exploring calm lakes and gently flowing streams to river rapids and ocean waves—or even for trying cutting-edge wind sports. But the advent of inflatable SUPs has opened up this activity to many more people who don't want to put a roof rack on their vehicle and then transport a bulky non-inflatable SUP.