Crabbing from the docks with conical hoop nets and if a guy is dropping them straight down any type of rope works fine. Polyester rope is softer and easier on the hands while hauling up a wet rope over and over during the tide swing, but it also costs a few more dollars. I prefer polypro for shore based crabbing because it floats if accidentally loose in the water, and a guy gets strong rope for relatively low cost. If you have a small float secured to the rope just above the hoop, which you probably were planning to do, you can frisbee the hoop nets away from the docks to get more space between you and the other guys rigs; and the float will keep the hoop net upright as it sinks. Floating rope like polypro helps even more with keeping the net upright as it sinks. I frisbee hoop nets off the jetty's. There floating rope is more important because it helps keep the rope from settling into snags and tangling around rocks. When a hoop net snags the bottom and a guy is on the dock or jetty there aren't many options to change the angle of the pull, so you just pull harder. I have had better success unsnagging hoop nets when working from shore and using floating rope. If brute force does not work I give it lots of slack and let it float up from the bottom for a minute, then haul as hard and fast as possible to try to get more vertical lift and less horizontal pull. It takes a few tries sometimes, but it works pretty well. My theory is that when pulling in a hoop net horizontally from shore the more vertical vs horizontal the initial pull of the the rope, the fewer crabs are able to slide to the side and get away when they feel things under them starting to move. It is just a theory. I have never tried to disprove it. I do catch a few crabs.