I use 17lb Seaguar fluorocarbon for both trolling and casting harness.Captain Eric explained on this same topic,that mono is more resistant to abrasion than fluorocarbon.Plus had a great utube demo showing it being tested.The popular thinking is that the fluorocarbon is more expensive but harder for fish to see.The opposing view is mono is cheaper and last longer.In the western basin the visibility is not as critical due to the muddy and stained water.