Check out this video of Blue Angel #5 shot last week at Fleet Week in San Francisco. It's a Boeing F/A-18 Hornet jet aircraft flying about 25 feet above the surface of the water, and creating what's called a Prandtl-Glauert condensation cloud. Not only is this jet jockey flying perilously close to the edge of the earth's surface, he also might be flying close to the edge of the speed of sound. If so, it's a good thing he didn't go just a little bit faster, or he would have broken every window in the vicinity with a huge sonic boom.
Under just the right conditions, this vapour cone shows up, often as a jet approaches the speed of sound, but other times even at lower speeds. In this case, he's probably not going that fast, and kicking up some vapour from the water. But it looks cool nonetheless. And video shooters, check out how much faster the jet appears to be going when the videographer lets the aircraft fly into the frame and then quickly begins panning along with it. Spectacular. [Blue Angels, via Jumpcut]