With respect to the tandem anchoring technique in the OP, this article was essentially lifted from chapter 6 (pg 173-174) of the Voyager's Handbook second edition; "Some situations demand extra holding power, more than can be supplied by the primary anchor. This can be the case in some crowded Mediterranean anchorages, where it is not possible to put out adequate scope for the conditions. It can also be the case on a bottom with poor holding or in very high winds. In these situations, setting two anchors in tandem on the same rode provides additional holding power and will keep the primary anchor from dragging
." ... "Tandem anchors are a common solution in Chile where high winds and rocky, kelp-covered bottoms cause anchors that have worked successfully everyplace else to drag
I initially found the description of this technique in the book confusing, and had to re-read it several times before I understood. Seeing it again in CW reinforced the idea.
Alex's illustration, and explination were far clearer than those in either the Voyager's Handbook, or CW. Maybe he should be a consultant on the next version?
Finally, and I don't like going here, by stating that anyone's practice (never mind two well respected authors);
is incredibly ignorant and should be condemned. I cannot state this point forcefully enough.
is the beginning of another pissing contest...
The OP asked if anyone had experience with the tandem anchoring technique. Alex stated that he did have experience with this technique, and he explained it very well.