Open water accidents you've experienced?

I'm hoping to swim in open water some day. Just read some articles about what to pay attention to and all sorts of accidents that can happen--losing goggles or cap when the race just started, for example. Some people bring an extra pair of goggles and wear them on their ankles or necks?? It will be interesting to hear what kind of accidents people have actually experienced in OW swimming--goggles/cap accidents, cramps due to cold water, losing direction, animal bites, needing rescue... And if you had the rare chance to see what the inside of the stomach of a shark was like that would be exciting to hear :D