Anchor weight and Length

[deanowens1966]

I have a 6.2m(20ft) sailboat and I am looking to replace the anchor and rode. I have selected a plough anchor and wanted to know what is the best length of rope and chain to use on Brisbane Waters an on the Central Coast of NSW.

Is 10m 5/16 gal chain and 50 m 3ply poly is sufficient?

I don’t have a huge budget to work with and prefer to buy from local distributors, if I can.

[tkeithlu]

6mm/ 1/4" chain would do. Ploughs (and their modern iterations) are probably the best general purpose anchors, although you can get into endless debates on that, because different anchors are best for different bottoms, and it's really hard to get good data on their performance. That leads to people arguing for one or the other based on their personal experience. Length of rode is a matter of depth of water and drag due to wind and current. 4:1 (rode:depth) is a common minimum, with arguments over longer than that and even height of the bow above the surface. Rode then depends on how deep you want to anchor, and under what conditions.

So, develop your own experience with your boat, anchor, rode, and conditions. Always set an anchor alarm in case you misjudged on the wrong side of the equation. Good luck with it.

[tkeithlu]

Nylon would be a better choice than poly. It's stretchy, with 30% elongation before parting. That reduces shock, which can jerk your anchor out of the mud and you out of well-deserved sleep.

[GordMay]

I presume the OP is intending to sail the “Brisbane Water”, which is a few hours' sail north of New South Wales's capital city, Sydney; as opposed to the waters around Brisbane, Queensland.

[sail sfbay]

Originally Posted by deanowens1966

I have a 6.2m(20ft) sailboat and I am looking to replace the anchor and rode.............. Is 10m 5/16 gal chain and 50 m 3ply poly is sufficient?...........

chain - 3/16" diameter 20 ft (one boat length) minimum and 50 m of 3/8"

three-strand nylon line - 3/8" diameter 150 ft (1/8" of diameter for every 8' of boat length) will allow you to anchor in 24 feet of water for 7:1 scope. For deeper anchorages select chain + rope length to meet 7:1 scope.

https://www.westmarine.com/WestAdvis...An-Anchor-Rode

[Djarraluda]

Originally Posted by deanowens1966

I have a 6.2m(20ft) sailboat and I am looking to replace the anchor and rode. I have selected a plough anchor and wanted to know what is the best length of rope and chain to use on Brisbane Waters an on the Central Coast of NSW.

Is 10m 5/16 gal chain and 50 m 3ply poly is sufficient?

I don’t have a huge budget to work with and prefer to buy from local distributors, if I can.

In simple terms -Maybe! As others have stated, you need max depth plus bow height out of the water, then 4 to 5 times that all for the overall rode. All chain will only need 3 times.
Most anchoring depths will be about 5m or less so with your 60m suggested you have adequate margin. I would stay with the heavier than necessary chain you mention but use a nylon rode not poly. The W.... chandlers have selection charts in the catalogue.
Choose the anchor well though. Most of our local chandlers have stocks of the old plough type, copies of the CQR and these are only just OK, the more modern variants are so much better.
Roger

[Ramona]

Originally Posted by deanowens1966

I have a 6.2m(20ft) sailboat and I am looking to replace the anchor and rode. I have selected a plough anchor and wanted to know what is the best length of rope and chain to use on Brisbane Waters an on the Central Coast of NSW.

Is 10m 5/16 gal chain and 50 m 3ply poly is sufficient?

I don’t have a huge budget to work with and prefer to buy from local distributors, if I can.

10m of 8mm chain is way overboard for a 20 foot Spacesailor. That's a lot of weight up on the bow just where you don't want it. Also pulling 10m of chain plus the anchor vertically by hand is going to be hard yakker! I would suggest 3m of 8mm chain with a light high holding anchor [not a plow] and 50 of 3 strand silver rope[poly]. Choose the diameter that's best for your hands. You have to decide whether you want to be able to sail this yacht or cart about a lot of chain that's just going to kill performance and rust up in the anchor locker.

[boatman61]

I would suggest a 10kg anchor, 60ft of 6mm chain and 15metres of nylon rope in a cockpit locker for if you ever need to anchor in deeper water.
But then I am an all chain man..

[Jim Cate]

I would suggest 3m of 8mm chain with a light high holding anchor [not a plow] and 50 of 3 strand silver rope[poly].

I strongly advise against silver line as anchor rode. Any floating line is a poor choice for anchoring because when the strain comes off it (and that is not an uncommon event) the slack floats on the surface and is a hazard to all nearby vessels, to say nothing of the chance of fouling your own keel or prop.

I do agree that deliberately starting out buying a plow anchor is a bad call. Any of the new generation anchors will do a better job... especially if compared to the ubiquitous sleazy knock-off "CQR" look-alikes offered by Whitworth, etc.

Jim

[Ramona]

Originally Posted by Jim Cate

I strongly advise against silver line as anchor rode. Any floating line is a poor choice for anchoring because when the strain comes off it (and that is not an uncommon event) the slack floats on the surface and is a hazard to all nearby vessels, to say nothing of the chance of fouling your own keel or prop.

I do agree that deliberately starting out buying a plow anchor is a bad call. Any of the new generation anchors will do a better job... especially if compared to the ubiquitous sleazy knock-off "CQR" look-alikes offered by Whitworth, etc.

Jim

I agree with the sentiments of the silver rope, I was trying to keep it cheap as per the first post. I personally would use secondhand 12 or 14mm double braid. Easy on the hands and stows easily in an anchor locker. Most of his anchoring will be in 3 or 4 metres of water. The Spacesailer 20 is a reasonably light trailer sailer that is also available as a fixed keeler.

[deanowens1966]

This is the fixed keel version and I do believe I would be anchoring in no more than 5m waters.

[psk125]

There is no point in getting huge amounts of chain if you're no more than 5m water. Nylon twisted line, as others have suggested, stretches. This avoids shock loads on both the boat - where they can rip out fittings - and the anchor, which can be dislodged. Braided line stretches less, and chain less than that. (You don't really have enough depth to develop a sufficient catenary to have that serve as your "cushioning", with chain. A short length is helpful in getting the anchor to set. We have about 7m of chain for our 36' boat, but that's what works around HERE. Ask around to see what anchors work best THERE. You're getting advice here from people who anchor in kelp beds, on granite shelfs, on rocks, in mud, and in sandy bottoms, all over the world. YMMV!

[Ramona]

The limitations in this case is what is going to fit in the anchor locker. A small rollbar anchor wont fit and I think the best anchor in this case would be a 6 kg sand anchor. Ideally a Manson aluminium sand anchor. Whitworths call them the Manson racing anchor and they would be good in this case. Keeping it cheap go for the galvanized steel version. I would suggest measuring up the locker carefully and even make a plywood version of the anchor of your choice to ensure it fits.