When you want to signal your buddy or another diver, point the light of the underwater light at the diver's body or in the diver's field of view and shake the underwater light so that it wiggles.

If the diver doesn't notice the light of the underwater light, touch the buddy's arm and give a signal。
Don't touch the diver's feet when you touch the diver, so that your diver's fins don't get your head caught.

Night diving hand signals are made by illuminating your hand with the light of an underwater light.

If there is a person next to you, you should illuminate your chest with a light and give a hand signal in front of your chest so that you does not accidentally illuminate the person's face.

Let's talk about the hand signal of one hand before diving.

Also, the light of the underwater light may be used instead of the hand signal.