As nights get dark, we need to be very visible on the water. The clippers go so fast they don't have long to scrutinise the shadows. It freaks them out to sea lurking kayakers at the last moment. On last weeks trip, I was at the back with five paddlers in front of me, and all were dark, only visible if you knew they were there. We must to better!
So, regular river paddlers ought to ask Santa for an all-round white light for the rear deck. If head torches are used at least half of the group should wear theirs facing backwards, or wear two one forward, one backwards, they are cheap and featherweight these days . LED lights designed to attach to cycle rucksacks, saddlebags, etc are small, cheap, and easy to stick on somehow, again backwards is probably more important than forwards. They would still be there after a roll too, which head torches would not be. It is time to get imaginative. The first paddler with an illuminated christmas tree or santa on the boat (that stays lit throughout the trip, even after we push them over) wins a beer.