The Smartfin is a surf and paddle board fin with sensors that measure multiple ocean parameters including temperature, location, and wave characteristics. The data surfers and paddlers acquire while in the water will become accessible in near real-time to the world-wide scientific community. But Smartfin is not only about the data. It is also an effort to connect ocean lovers and their communities to larger issues affecting ocean health. Using the data collected with Smartfin, we can better understand trends in ocean warming, acidification, and sea level rise, and mobilize our communities to take action to combat these problems caused by climate change.