How Much Scope?

[Zanshin]

I must admit that when conditions permit and no other boats are inconvenienced, I put out as much chain as I can. Anchor chain in your locker is (to use an analogy from flying) as useful as runway behind you and altitude above you.
I'm currently writing this message from Great Harbor on Jost van Dyke in the BVI. The holding here is known to be mediocre at best yet yesterday afternoon I watched the charter fleets come in and spend a lot of time anchoring - at least those who were prudent sailors did, those who dropped 40 feet of chain in 20 feet of water and turn off the engine in order to get back to partying were saved only by the fact that the wind died down to almost nothing last night.
I like to use the sole of my foot to "feel" the chain when getting the anchor set initially and before letting out sufficient scope. This initial setting is, in my opinion, what separates the experts from the rest of us - if you let out too little chain initially the anchor can't set and will always drag, too much chain and the friction of the chain itself on the bottom might preclude the anchor from setting. I've got exactly 100 feet in 30 feet of water right now and don't feel too bad, but only because if I were to drag it would be towards shallower water which would effectively increase the scope at 20 feet to 5:1. Now I just have to wait for the charter boat that anchored over my anchor to disappear so that I can leave (it took them so long to anchor yesterday that I didn't have the heart to ask them to move).

[mrohr]

Originally Posted by s/v Jedi

I am all confused... this is a 39' boat without windlass, a 35 lb CQR with 30' chain and the rest rope? Oh my, advice is easy here:

1. Buy and install electric windlass.
2. What does a Cal39 weigh? Buy a Rocna 33 (that's 70 lbs!).
3. Put 250' of 8mm - 5/16" HT chain on that
4. Set it at 5:1 using engine at half throttle or so
5. Sleep well

ciao!
Nick.

wait! a bigger anchor will require a windlass that requires more electric that requires more solar panels that requires more windage which puts more strain on the boat which requires... maybe just more chain?

[Nice N Easy]

I have no experience with anchoring in rocky conditions, nor in water 50' deep. Here on the gulf coast, 20' is deep water, and most ancorages are less than that. I don't belong to the 4 to 1 or 7 to 1 or whatever scope that others do. I always use at least 10 to 1. I like to sleep without worrying about dragging. If an anchorage is too crowded to use 10 to 1 or more, I simply move to another location. You cannot have too much scope.

[Fuss]

Originally Posted by Don Lucas

Motored up to the area and looked it over and asked another boat that was there how the holding was and how much scope he had out. He said his plow was holding well and he had a 4:1 out.
So we dropped the hook, played out a 4:1 based on bow roller height, drifted back and then powered up to set. Since I had been playing with the GPS I set the anchor alarm and also marked the spot I was at so I could see the track). During the next 4 hours the wind was light and we appeared to be set and not dragging. Since we had dropped at low tide I decided to let out some more line, but could only do so much as if the wind shifted I would swing into the guy next to me.
A couple of hours later was awoke to the sound of lines banging. We had swung with a wind change and the wind was at 20 knots (was like 5-8 when we dropped), but we looked to still be set (was now 1 am of course and high tide was in 20 minutes).

10 minutes later he dragged.

Here's my 2 cents worth..
I these days think that asking others what they think at anchor is only a guide and at the end of the day you have to decide for yourself whats right.
I think that you have to feel confident enough to leave your boat during the day to go sight seeing and at night not to end up on the rocks.
Ive dragged a few times in the past and so I made changes until I now sleep through most nights at anchor. In all of the circumstances, I think more chain would have been the cure, not a bigger anchor, at the time I had a 70 pound anchor.
Don Lucas set his anchor in 5-8kts of wind, you can't drag in that so the comment by the other boat that his plow was holding well was meaningless. Later his boat dragged in 20kts, which I consider light and it should not have dragged. Maybe he did not pull it in hard enough with the motor, I pull mine with more than half revs for 2 mins. I would have tried to have more than the 4 or 5 to 1, maybe 7 to one.
These days I expect to sleep through 20 kts and get up occasionally with more than 30kts, but still sleep some of the time.
I expect to feel confident at anchor in 50kts but I would not sleep.
I only ever use one anchor as I like simplicity if theres an emergency. I have a 40,000 pound boat and now a 120 pound anchor.
Often people say my anchor is too big, but I don't have many anchor moments these days and so it makes me feel much more secure than I used to.

[imagine2frolic]

Chain has weight to it also, and it doesn't take long for it to add up........i2f