Anchor doesnt hook up

[BrendanS]

How would you attach a heavy chain to such a piddling anchor?

A bit of monofilament or green garden twine would probably suffice!

 

[john_morris_uk]

My boat came with 20m chain plus 28m of rope. We regularly anchor in 24m depth, chart datum. That becomes 28+ metres at high water, to which we should add another meter from water to bow. So 48m warp would be woefully inadequate -- multiplying 29 by 3 gives 87m as a minimum recommended scope for that depth.

We now have 70m chain plus 50m rope (and another 50 lurking in the locker), which is quite adequate for the depth of that anchorage. In anything up to F5 or so that is sufficient. Above F5 we are in port anyway !!!!

I don't want to stir thing up too much, but Tim Bartlett is right. The multiples of depth rule is not a rule, but a guide that works in shallow waters. In deeper waters the multiples don't work as well. In fact you need less chain than you think as the water gets deeper and deeper. Its partly to do with the weight of the chain hanging vertically in the water and the force that's needed to lift it off the bottom to allow the anchor to start dragging.

(By the way this is the first time I have ever posted on the Mobo forum - despite being an occasional motor boater myself!)

 

[Plomong]

(By the way this is the first time I have ever posted on the Mobo forum

I think it was also my first post on this forum, IIRC !!!

The multiples of depth rule is not a rule, but a guide that works in shallow waters. In deeper waters the multiples don't work as well. In fact you need less chain than you think as the water gets deeper and deeper. Its partly to do with the weight of the chain hanging vertically in the water and the force that's needed to lift it off the bottom to allow the anchor to start dragging.

Yes, I'm very much aware of that -- that's why we have so much chain. The chain weighs 100+ kg, way above that of the anchor itself, and in benign conditions is just straight up and down at the bow roller.

Have just prepared an anchor buoy with automatically adjusting buoy rope so we can see roughly where the anchor is and get a feeling for how we are moving about relative to the anchor as the wind or tide changes.

 

[Wiggo]

Here's the proof that the anchor doesn't even need to set. If you look carefully in this photo you will see a vertical chain from the stemhead roller, a perfect catenary of chain to the bottom and lots of scope holding the boat fast. If you look closely you will notice the anchor hasn't even set, yet the boat is clearly going nowhere: