I was wanting a more subtle effect with the kayaker immersed in the dark. Using a flash say at 1/8th power is a little problematic because of the light fall off making the stern overly bright and the rest dark and the tendency for it to pick up reflective parts of cords, PFD's and deck bags. A little light painting with a headlamp from an angle works a little better or just using Photoshop to add light to the picture. I have added 3 pictures, with the kayaker I have just added light in processing, the two pictures of people sitting are light painted with a headlamp. What I am really considering the next time is to add a slight flash or light paint from out of frame on the left and from in front of the kayaker so I can get a delicate rim light. That would help define the kayaker but still capture the darkness aspect of the picture.