You know, every boat I ever fished on over 50 feet uses chain and cable. I don't think that cable stretches. I did call Novabraid before I posted. The guy there seemed to think that because the working load limit of the rope was so much greater than that of the chain that it should be fine as anchor line. He did not try to talk me into going back to nylon. He said I was correct in assuming no shock mitigation but that the line would not break. I'm thinking that you guys are correct. I don't want to stress out the entire system. If I go with 5/8 double braid my chain will likely end up being reduced to around 50' and my rode to 150'. That's half the available scope that I have now. I'll look into down sizing the chain to 3/8 grade 43 to regain some scope. As far as plait goes... I just now looked that up. Working load limit for 5/8 is only 932 lbs. http://www.unirope.com/fiberropes/fr...lonbrait.shtml
That's much to light.