The evidence points to holding power being roughly proportional to anchor weight (if we compare anchors of the same design and material).

You said exactly the same thing in one of your recent magazine articles on anchoring, so I am not sure what has lead to the change of heart:

**"A final argument could be suggested that bigger anchors will work better. This is valid and roughly twice the weight will produce twice the hold" (Jonathan Neeves Cruising Helmsmen magazine November 2015). **
For experimental results you can look at the work done by Prof Knox. His conclusions are:

**"The maximum holding of an anchor, as recommended by manufacturers, is proportional to its weight. This is precisely what I found by direct experiment" (Prof Knox PBO magazine August 2002).**
You can see for both the tested Delta and Bruce, as you double the weight you double the hold:

Or you can look at the results from the Vryhof tests. These are for very large anchors. Their results indicate doubling the anchor size increases the hold by 92%. Their formula for hold verses anchor weight is:

Ultimate holding capacity= A*(W)0.92 where W is weight and A is constant based on the anchor design and substrate. In graph form it looks like this. The slope is not quite 1.0, but is very close:

Or you can look at results published by the anchor manufacturers. This is from Rocna, showing the anchor manufacturer expects a 20kg anchor to have double the holding power of the 10kg model. (The 44 lb Rocna model holds 1122 lbs in this substrate the 22 lb model hold 1/2 of this or 561 lbs)

Holding

Power(lbs) .......Weight (lbs)

229 .................... 9

331 .....................13

561 .....................22

841 .....................33

1122 ...................44

1402 ...................55

1861 ...................73

2244 ...................88

3085 ...................121

3927 ...................154

6196 ...................243

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