I'm not sure there needs to be a difference. Whether it's an rov with fibers/conductors and synthetic rope, or just a synthetic rope, it's still just a big winch and there's nothing weird about the length. There's something different going on with that white stuff. It looks like it's almost the size of someone's forearm, but you wouldn't need something that size. Being tetherless, they already have to hook it no matter what, so if you just need to raise something to the surface to hook it, you don't actually need it to be very big.