I'm not sure either. When I first outfitted my pram, I used yellow propylene, then braided white curtain cord, and finally 150 lb clear commercial mono trolling line. I have stuck with the mono. I have to wear gloves to haul line, but that isn't a problem. I caught fish under all three anchor systems, but I like the mono when fishing really shallow bottom contours. When my son was younger, he went over the side for a swim and a look and he said he couldn't see the mono.