I guess I've always thought that rope would snap off of the chain easier than just one long constant chain. I also wonder how rope holds up after being constantly subjected to water, and whether it loses some of its strength and integrity. My windlass will accommodate both chain and rope. I'd hate to lose another anchor based on poor rode integrity.
In the case you mention then, all I would need is rope, given that I already have 80' of chain. I'll have to see if its possible to find the correct rope and if its possible to braid rope onto my existing chain.
Lake Hartwell, GA