T&T: Anchor Size Recommendations

[C. Marin Faure]

 >We had a 66# Bruce on our 44 Defever and now have a 110# Bruce on  
our 46 Nordhavn

I'm sure if we carried a 110-pound Bruce on our GB36 we would not  
have experience as much dragging as we did :-)  But an anchor this  
large would not even fit on our pulpit let alone allow me to  
manhandle it into place, to say nothing of requiring a larger  
windlass than our Lofrans Tigres.  I have read more times than I can  
remember anchoring experts saying that while weight is a very  
important factor in helping an anchor penetrate the bottom and set,  
it is not the main factor of an anchor's ability to hold once it is  
set.  According to these people who know a hell of a lot more than I  
do, holding power is almost completely fluke design and how it acts  
in whatever the bottom material is.  If weight was the primary  
consideration of an anchor's ability to hold, the Fortress would not  
work.  Yet it is consistently rated at or near the top in terms of  
holding power in the types of bottoms its design is suited for.  If  
my choices are a huge size and high weight to overcome a basic design  
deficiency or a new, modern design that provides equal or better  
setting and holding with a weight 1/3 or less of the monster anchor,  
guess which way I'm going to go.

While researching what would be the most effective replacement for  
our Bruce, it was very interesting to read the reason spade anchors  
like the Rocna are designed the way they are.  The Rocna is designed  
to end up in a very specific position on the bottom (hence the roll  
bar which puts it in this position no matter how it lands) at which  
point it uses high leverage, a skid plate, and a very sharp point to  
ensure penetration into the bottom.  Once the point has penetrated,  
the design of the shank and fluke forces the anchor to end up in a  
position that puts maximum resistance against the force trying to  
pull it out of the bottom.

If the Rocna was brand new to the market I, too, would raise my  
eyebrows at the claims made for it.  But it's been around for quite  
awhile now and has garnered an impressive array of testimonials.   
What impressed me when we started looking into the Rocna was who the  
testimonials were from.  They weren't from coastal cruisers who drop  
anchor in a quiet bay where the only pull on the anchor is the  
current and the wake from a passing ferry.  They seemed to be mostly  
blue-water, long-distance cruisers, many of them sailboaters, who  
anchor in wide open, exposed anchorages in the southwestern Pacific  
over a variety of bottoms, from sandy to rocky.

Again, I'm not going to claim that the Rocna is superior to every  
other anchor type out there.  But the notion of carrying a huge,  
heavy, oversize anchor simply to ensure that it will hold makes no  
sense to me when there are anchor designs out there now that allow  
one to carry a reasonably-sized and weighted anchor for the boat and  
have as complete a confidence in its reliability as it's possible to  
have with any anchor.  I am well aware of the "you know your anchor  
is big enough when people on the dock start laughing at you," quote,  
but I suspect the person who made that statement made it a long time  
ago when the only anchor choices were the so-called legacy anchors.

People sometimes use commercial fishermen as an example of why a  
huge, heavy anchor is the best.  I don't buy into that argument with  
regards to what's best for a recreational trawler.  We have a bunch  
of purse seiners and combination boats based in the commercial part  
of the harbor in Bellingham.  Yes, these boats have big, heavy  
anchors most of which seem to be a variation of the Navy anchor.  But  
we're talking massive, 58' foot, full-displacement working boats here  
with huge, powerful winches on the foredeck for the anchor.  These  
boats could hang a pickup truck on the rode and  be able to deal with  
it.  From talking to a few crewmembers about their anchoring  
technique up north they said they simply dump the anchor "and a  
sh*tload of chain and cable" onto the bottom and call it good.  There  
is so much weight down there it probably doesn't matter in 90 percent  
of their anchoring situations if the anchor is actually set or not.   
Sensible solution for them, not so sensible for the CHB or Nordic Tug  
or Grand Banks owner.


____________________
C. Marin Faure
GB36-403 "La Perouse"
Bellingham, Washington