danforth anchor size recommnedation....?

[photographer]

I have a danforth anchor for my Wellcraft 180 Sportsman. The anchor is about 6-7 pounds. It is fine when water is calm. However last Saturday when it was choppy, wind 20 knots, the boat started dragging it. I live in Miami, so the bottom is sandy.

What size anchor do you recommend so the boat won't be dragged again? Thanks so much and I apologize if the question is too basic.

 

[alldodge]

I have a danforth anchor for my Wellcraft 180 Sportsman. The anchor is about 6-7 pounds. It is fine when water is calm. However last Saturday when it was choppy, wind 20 knots, the boat started dragging it. I live in Miami, so the bottom is sandy.

What size anchor do you recommend so the boat won't be dragged again? Thanks so much and I apologize if the question is too basic.

With sand your Danforth should be fine, your issue in most cases is you probably don't have enough chain between it and the rode. Need at least 10 but 20 foot of chain is better for your 18 foot boat. Need to have enough rode out for at least a 3:1 slope. So 40ft need 120 feet of rode. The key is the amount of rode out to allow the anchor to lay flat on the bottom.

You could try a plow which will continue to dig in, but it still needs the same amount of rode

 

[airshot]

ALLDodge's info is right on, those types of anchors do need chain weight and correct rode length to work. I had the same issue so I tried one of the CHENE anchors and found it to work better with less hassle. They say no chain is needed however I have found a short chain works better with them but a smaller anchor holds a bigger boat with their design. So far (2nd season) I have left the Danforth at home and choose the CHENE on windy days.

 

[Chris1956]

OK, 18 footer....5-6 feet of galvanized chain plus 3/8' 3 strand twisted nylon anchor line, equal to 4-5 times the depth of the water, ought to hold in all but gale conditions. Look on the Danforth anchor website for the anchor size recommendation. Go up a size if unsure.

 

[shrew]

I agree with all except scope. 3:1 is good for a lunch stop or with no wind or current. I personally wouldn't sit at 3:1 unless it was for a few minutes or an emergency. I'd prefer 5:1 in calm conditions. In 20kts of wind I would be laying out 7:1. This might be tough in really deep water. I don't fish while I'm sitting on anchor. I drink, cook, eat, read, play cards and I sleep. I will sit on anchor for multiple days or a week at a time.

Chain equal to the length of the boat is a good standard. I'll dive on my anchor. Even in 20kts of wind, I like to see the chain sitting on the seabed placing a horizontal pull on the anchor.