Mostly it depends. I will most often just dive using my focus light as a light source. Dim, but once your eyes get used to it that is all you really need. I do carry a dive light and if I need more light I just carry it in my left hand and use that hand to both hold the camera and the light. I will drop the light on a lanyard temporarily if I need the hand for more than steadying the camera. I have video lights as well as two strobes so if I really need light I will turn on the video lights, but even just one is way too bright even at its lowest setting. My camera and strobes are very close to neutral so if I need to I can hold it in one hand.