On a family outing to the Lewis River, a bit north of Vancouver, WA, my son Joshua and my 15-year-old grandson Israel decided to take two of my inflatable kayaks down a stretch of the river with a reasonably swift current and some mild rapids.
We were in a shadowed forest area about an hour before sunset, and I decided that due to the dim light I should use my Canon 580 EX Speedlight. I'm not experienced in this kind of flash work, so I had to mess around with the settings. In the first two close up shots I used the flash bounce card for milder lighting, but when the rafts went by I decided on direct flash. I upped the Flash Exposure Compensation a bit and kept the shutter speed low to try to allow as much ambient light as possible but still illuminate the guys at some distance, but the flash was amped a bit high and I had to do some real work in LightRoom to compensate. RAW shooting power!
Anyway, we weren't at any of the rapids to get the best shots -- that'll come next time!