When I was swimming, I heard a sound, similar to static electricity. What was the situation then?

Water itself is a conductor. If there is leakage in the swimming pool, not only swimmers will feel electric shock, but also the power supply system should have leakage alarm, which is a safety measure that should be considered when designing swimming pool lighting. When you hear the crackling sound, it is not necessarily the sound of electrostatic discharge, because the environment that generates static electricity must be a dry environment. The swimming pool is full of water, which can conduct electricity and has a certain area, so it is impossible to generate static electricity in the swimming pool. The reason is that static electricity has a high voltage. With a little humidity, positive and negative ions will be short-circuited through humid air, so high voltage cannot be accumulated. The lightning we see in nature has accumulated a high electrostatic ion cloud, which is quickly moved into the humid air by the strong airflow in the air, resulting in a sudden discharge (short circuit). For the above reasons, what you should hear is the sound of water leaking into the sewer.