A combination Chain/Rope Anchor Rode may prove to be the optimum arrangement
The scope of the chain should still be more than adequate for anticipated anchorage depths and weather conditions.
The extra length of the rope extension will not only increase the scope, but also provide valuable shock absorbing capability if conditions seriously worsen.
Relatively more scope is require in shallow water or in rough conditions. The aim is to keep the pull on the anchor horizontal and provide shock absorption.
When using two anchors the greater the angle between them the smaller the rurning area.