Duck diving is one of the most revered feats when dealing bodyboarding an conquering waves. If you want to be a King or Queen of the waves, read below!
First, paddle towards the wave to gain some speed. Timing is important because you need to have a few feet of distance between you and the wave when you begin to duck dive.
Grab the rails of the board, then put your knees on the tail of the board. Push the nose below the water and lean forward with your head down. At this point, your position should look like the one in the picture below.
Hold your breath, go head first under water and lean forward. Frequently you will find that the whitewater hits your back as you go under, helping you to duck dive. That is a good sign; it shows how close you will be to the wave in the duck diving process at this point.
The wave is now behind you and you will change angles by leaning your board and body upwards, shown in the picture below. By leaning upwards, the buoyancy will carry you to the top.
Re-center yourself on your board, paddle, and look ahead for any more oncoming waves to duck dive!