Only a few centimeters of ice separates you from the freezing water. If you fall, you will get shocked by the cold water within the first minute. In less than ten you will be incapable of doing anything.
What you see in the picture a guy diving with a Whale Shark, the largest known fish. They can be up to twelve meters long. Let me tell you that these kind of sharks are not dangerous at all, they are actually very playful with human.