Not very good quality - but essentially it says the best devices at night are the Dolphin Touch (shone at an oncoming vessel, on a sail or your body) and the Hella 2 nautical mile all round light. Lesser lights are almost ineffective. Every kayaker knows that the paddle is the first thing to be seen during the day because it is the highest part out of water. Some paddles have reflectors built into them. More recently, the introduction of fluro hats is very effective during the day. Reflective tape is modestly effective during the day if it is on the highest part out of water - the paddle. At night it is ineffective unless a light is shone at it.