I have read one more test anchor, a recent one, this time on the British Magazine PBO (Pratical Boat Owner). The anchors were the usual including Rocna, Manson, Spade, CQR, Bruce and Delta but this test was a bit different, more complicated and they did not limit themselves to pull the anchors till they drag (DHF). They not only normalized the results but also found the Ultimate Holding Capacity (UHC) that is smaller than the Dynamic Holding Force, but more reliable and useful.
The overall conclusion was the usual, the Rocna, Mason and Spade are great anchors. If we want to be picky the Spade was the best performer.
They used a complicated system to determinate the UHC that is the minimum force needed to move the anchor and that is different from dragging. Good anchors move very slowly on the bottom resisting pressure and we don't call normally that dragging.
That means that they had pulled the anchor till it moves then they will stopped pulling without diminishing the pressure till it stops moving slowly on the bottom and stays stationary. They have made this sequence 6 or seven times. The Medium value is the normalized one. The anchors were tested 1m apart and were tested several times and on two different grounds: Hard Sand/Mud and Medium hard sand.
Then they have attributed an efficiency index to the tested anchors. For that they divided the UHC by the weight of each anchor. The anchors were tested in about two different approximated sizes 6Kg and 15kg but as all the anchors had not exactly the same weight they introduced this efficiency concept to give more precision to the test.
Complicated? Is what happens when you put a University physics professor doing the job
One of the conclusions that is nice to know is that the efficiency of the bigger anchors is about 30% better than on the small ones. The efficiency numbers are these (the smaller number for the less efficient smaller anchor, the bigger one for the heavier and more efficient one):
Spade 24; 32
Rocna 21; 30
Manson 12; 21
Delta 8; 11
Bruce 5; 6
CQR 7; 8
Regarding setting the anchor they say :
Excellent for Spade, Rocna and Mason.
CQR - Dragged on surface;
Delta - moderate/good;
Bruce - Dragged on surface.
Spade, Rocna and Mason: Excellent performance
Delta: Good performance
CQR and Bruce: Poor performance.
I will add something that is very important:
The similar sized Spade, Rocna and Mason anchors have, as the numbers show, a close performance however Spade, for the same size of boat recommends heavier anchors than Rocna and specially more heavier than Mason that seems a lot more optimistic about the holding power a boat needs.
Some prefer to buy Mason because they just recommends less heavier and therefore less expensive anchors for a given sized boat, comparing with Spade and Rocna. That only means that those sailors are trusting on the more optimistic seller since the holding power is very similar on similar weighted anchors made by these manufacturers.
Even if the holding power of Mason is very good it is inferior (not only on this test but on more tests that I had saw) than the one from Spade or Rocna and I find funny that it is the one with less holding power that recommends the lighter anchors for the same boat.
Do you think it does not make sense? Yes it makes sense on a commercial point of view because there would be some sailors that would believe that because they are more optimistic their anchors have more holding power than the ones from their close competitors.
Regarding optimism and sailors there is an old saying: The bottom of the ocean is full of optimistic sailors