They were designed so a live baitfish could be hooked through the back and allowed to swim freely, hence the name, bait runner (which Shimano patented), and a lot were destined for saltwater fishing. My 6500 would be a great reel for sharks, and that whole series featured waterproof drag so they could be rinsed. I don't think carp anglers were even considered at first, they just picked it up, but I could be wrong. In any case I think they're great.