multi's benefit from a decent weight of cable - not just a heavy anchor. I use 3/8" when the spec is 5/16" or less. I find that dampens the sailing around significantly and also is a major help in preventing anchor breakout on tide change.
However the extra weight of cable (or an anchor chump i.e. a weight attached to the cable) is not the total answer. A bridle will help enormously, especially if the cat is a wide one. You have two choices, you can set the bridle up so that you are lying directly behind it, or you can offset somewhat so any movement will be in one direction only. But dont forget that your bridle is going to be susceptible to chafe. On my
catalac I normally dont bother with a bridle unless in a really confined anchorage, hopefully before you see the look of anquish on the face of somebody who has anchored after you and too close for a cats characteristics!