Garmin's Vivoactive Is a Hybrid Sports Watch and Smartwatch - Vox
Amazon.com: CA0440 Blue Water Swimming Pool Leather Smart Watch Band Strap for Garmin Vivoactive 4S Vivomove 3S Size (18mm) : Electronics
Amazon.com: Garmin Swim 2, GPS Swimming Smartwatch for Pool and Open Water, Underwater Heart Rate, Records Distance, Pace, Stroke Count and Type, Slate Gray : Electronics
Garmin enables optical heart rate for swim on Vivoactive 4 & Venu