STORES HEART RATE UNDERWATER AND FORWARDS DATA Take your training to the next level by pairing HRM-Swim with your Forerunner® 920XT. Specifically designed for use in the pool, the sleek, non-slip strap stays in place, even during wall push-offs. Once you're out of the water, including when the torso is lifted out of the water mid-session, real-time heart rate, interval summaries and stored heart rate are transmitted to the 920XT.