The USCGC Kimball, which is based in Hawaii, held a swim call on Wednesday. That's when the ship halts and allows crew members to go for a swim in the ocean. They posted a rescue swimmer and watchmen because it's always a bit dangerous to conduct a swim call.
Why? Well, there are sharks in the area. And while about 40 swimmers were in the water, an 8-foot shark swam up to them. One coastie armed with a rifle fired shots at the shark very close to his shipmates. According to Good Morning America, everyone made it safely back on board--including the unicorn floatie that you can see drifting at the end of the video.