How was the scene of giving birth underwater in Murky Sai Bu's film Revelation filmed?

This was all taken in a water tank, and the water was clean. You can open your eyes underwater. Give you a few examples:

There are many water tanks in the underwater studio, which are integrated with the floor. One of the outdoor water tanks has a 240-foot × 60-foot blue screen and also has underwater shooting facilities. The blue screen on the scene always provides the feeling of "from wet to dry", which can provide amazing visual effects for movies, TV and commercial advertisements. The baby in the picture sinks head first into the water, which is simply a natural beauty. In the upper right corner is the famous blue screen. In this context, various images can be made. The following is a successful shot of the car sinking into the water.