It'll protect from shocks and bumps and from the elements. It also keeps your equipment away from the prying eyes of thieves. And usually there's room for your still camera and film, as well. Water, especially salt water, can be a camcorder's natural enemy. But I've had a camera get sprinkled with a few drops of salt water and it destroyed the camera.
Salt water corrodes everything it touches.
If your camera gets wet, he advises that you turn it off and pat it dry immediately. Even a light drizzle can wreak havoc on a camcorder's delicate electronics. If you're traveling to the tropics and will be moving from an air conditioning to hot temperatures, give your camcorder ten or fifteen minutes to adjust before trying to shoot. If that happens, eject the tape and turn the camera off with the tape gate open so the camera can acclimate for fifteen minutes or so. Shooting Techniques Before beginning to shoot, Ericson recommends learning the limitations of your camera.