Most commercially available safety flags are small and not much higher than a kayaker's head. An option to increase your visibility in the daytime is to make a large safety flag out of ripstop nylon and clip it to the top of a spare fishing pole. I made a safety flag and light pole with a big flag out of an inexpensive Walmart fishing pole, which I described in a post at
https://www.northwestkayakanglers.com/i ... #msg164358, but it would be much easier to just mount a large safety flat on a spare fishing pole.