What is Swim Buoy? Open Water Swim Buoy (Swim Buoy) is intended to provide visibility in open water, safe place to float and rest, and storage of personal items. If you are an avid sea, lake or river swimmer, we strongly encourage you to check out this swim safety device. Just inflate, strap it around your waist and start swimming! Even if you are an advanced swimmer who is pushing the possibilities of the sport of swimming, swim buoy is always a bright idea. Swim buoy is also for people that swim in high boat traffic areas to increase their visibility to boats.