mncruiser
Senior Member
Thanks for all the great suggestions. Have not had a chance to anchor out yet but will report back!
Ranger58sb wrote;
“ IIRC, Fortress and SuperMAC both say to set at 5:1. As does Vulcan, another Rocna product. I think Delta says 5:1. ??
Haven't paid strict attention to others, but 5:1 has always seemed common, to me.
-Chris
You say what should be experts say anchor at 5-1. I say most of the time anchoring in SE Alaska and BC I use 3-1. And if it blows 50 knots .. go to 5-1. I’ve never had an anchor drag at any scope I’ve anchored at. Plety of draging while setting tho.
It’s almost like he says she says…..
And another thing about 3-1. You don’t know anything about 3-1 unless you try it several or more times. And you won’t as you say you always use 5-1.
If you use “common” methods you’ll get common results.
You say what should be experts say anchor at 5-1. I say most of the time anchoring in SE Alaska and BC I use 3-1. And if it blows 50 knots .. go to 5-1. I’ve never had an anchor drag at any scope I’ve anchored at. Plety of draging while setting tho.
Corrected for you. Plenty of ploughing the seabed while setting tho.You say what should be experts say anchor at 5-1. I say most of the time anchoring in SE Alaska and BC I use 3-1. And if it blows 50 knots .. go to 5-1. I’ve never had an anchor drag at any scope I’ve anchored at. Plenty of draging while setting tho.
As some may know we are currently on our Defever 49 in the Aegean Sea (Greece) and that area is known for the Meltemi winds. Normally speaking we would never come here, since Greece does not have an accurate weather forecast, but we have to get to Turkey to install the stabilizers. The Greek weather forecast is basically identical as it was 3000 years ago, in other words, your guess is as good as mine. Sites like Windy, Predict wind etc use the local information to generate nice looking animations, but they have nothing to do with reality.
This Saturday 2 bft was predicted and all of a sudden we found ourselves in 51 kts wind steady. Managed to find an anchorage, which offers a bit of protection, but while I am writing this we still have 40 kts steady 30 degrees off the port bow.
Luckily I have a lot of chain and we threw out 90 mtrs of chain in 4 meter deep water, together with our 50 kg Sarca Excel. We set it well and it holds perfect, also installed a double snubber and two land lines to hold us in place and to keep us with the bow in the waves.
This morning I wanted to know how the anchor had performed through the night. I was pretty amazed to see the first 25 meters of chain (measured from the water line) solid off the bottom of the sea. The next 20 meters was actually still moving and only after that the chain did not move at all. So a scope of 5 : 1 would not have made it. 4 + 3 = 7 x 5 = 35 meters chain would have been an advised scope. The anchor would most certainly been pulled out.
I know I overdid it with more than 12 : 1 scope, but in storms like this I am not taking any chances. 15 meters behind my boat I have the shore which is basically rocks, so I have no room to drag my anchor.
The only problem I have is .................charter boats. The boats that are rented for a week by people who mostly cannot anchor or even cannot sail. They come into the anchorage, don't check where the anchors are, they simply drop their anchor, put out the minimum amount of chain and leave the boat by itself. They are off to shore.
Two hours ago a 40' catamaran showed up, dropped their anchor without asking where my anchor is (missed us by 2 meters) and let out the bare minimum. Now he is lying right in front of my bow. If he starts to drag I have a catamaran on my bow, not looking forward to that and this night the winds are expected to increase to 6 bft (according to the forecast), but we now have the experience that it usually means 1 or 2 bft extra. Wind force 8 with a catamaran on your bow is not a good idea. Going to be a long night again.
This catamaran ahead of us is the latest in a long line of 'idiots on the water', being the charter crews. Last week I had my anchor pulled out 3 times on one day and twice I found a boat hanging on my anchor chain. The skippers completely clueless, even became angry when I called them morons.
Cruising in Europe can be fun, but charter season is horrible and the Meltemi winds make this part of Greece basically a nightmare. We have 14 hours of sailing, in 3 legs, to get to our destination, but it could take over 1 month before we will be able to continue. Whatever happens, we are not leaving this anchorage with wind force 5 or more.
Anyways, long story short. The 5 : 1 scope usually works, but be aware that in strong winds you better throw out as much as you can, it may save you, your boat and whoever is on it. There is no need to risk anything when it is not necessary. But indeed, you need to know how to set an anchor properly and .............having oversized equipment is also not a bad thing. We have a 50 kg Sarca Excel and 140 mtrs of 13 mm chain. According to the books that is too much for our Defever, but we are very happy we have it on board.
did you mean 7.5 feet from pulpit @ 5:1 = 107.527.5 feet from pulpit @ 5:1 = 137.5 feet.
Then have the same faith that we have that the light goes out in the fridge when we shut the door.
This setting issue is a common problem with the original Spade and Vulcan anchors that I have traced down to a scope issue on setting. Dont worry it is solvable. There is definitely a technique to adapt to: These type of anchors really need 5 to 1 or 7 to 1 let out, set as you normally would by backing down slow at first and then hard when it catches and then if you have more scope out than you want bring some in after a solid setting. If you deploy with a short scope the weight on the tip doesn't have the angle it needs to dig in and pull the spade into the sand. I confirmed this by snorkeling to watch. (The "keel" is the weight and you want it there) Note, I have never had this problem with the standard Rocna, only the Vulcan and the Spade. If you only have a short chain lead and the rest is rode you will want at least a 5 to 1 *always* and 7 to 1 is better. Don't forget to add in the anchor roller height off the water in your depth calculations to get the right ratio as I think the roller on the Mainship 390 is pretty high off the water. Then take the time to work on your technique. On any given day, pack a lunch and go out and try anchoring several times and try different places, even if you only move a half a mile each time. It should come to you, but like anything else practice is best. Not once or twice, but a couple of dozen times. If eventually you aren't able to get comfortable with the Vulcan, whatever you do don't go for the Plow (or CQR). All they do is plow the sand out of the way instead of digging in, esp on a boat like yours with a lot of windage. (Ask me how I know) The regular Rocna or the Mantus would do you better if you can get then to fit on the bow roller with the hoop. Otherwise, the Sarca Xcel. I don't want to make this an anchor debate (fist-fight) , these are ALL excellent anchors, and at the same time some work better for certain people and boats and situations than others. That is why I try and own and use quite a few varieties to the point where my family laughs about it right up until we are anchored on the boat in a big blow. I also anchor in new places and very windy conditions frequently. Another important question is what is your back up anchor? Mine is a 100lb. Luke. It is almost too heavy for me to assemble, but I know I have a solid backup in a blow.
Lastly, don't go by what other people have on the bow there. Most never use them for more than a lunch stop. I have walked down the docks there in Bayfield (and almost anywhere) and I see 40 ft boats with puny 15-20lb. Danforths. I anchored a bunch in the Apostles with a BIG Danforth and held fine, but if the wind changes in a blow, often tough to reset in that packed sand, same with a plow. People don't tend to upgrade anchors over time. I see $3m Hinckleys out here on Cape Cod now with diminutive 35 lb. Stainless CQRs. only good for lunch stops at best.
Oversize, long rode, practice sleep well. My recipe. Have a great season!
I have the exact same boat and anchor as the OP
Mainship 350
Rocna Vulcan 20 (44LB)
130ft 5/16 G30 chain
150 5/8" 3strand line.
What I didn't catch in the write-up is how scope is calculated. When we say "Anchoring in 20 feet".
Are we using the transducer depth or the true water depth?
Are we adding the extra 5 feet to the bow pulpit?
20 feet from transducer @ 5:1 = 100 feet
Adding transducer depth (+2.5 ft) and height to bow pulpit (+5 ft)
27.5 feet from pulpit @ 5:1 = 137.5 feet.
What scope when you attempt to set the anchor? We had a lot of trouble when my wife first started. She would wait until the anchor hit the bottom, then would pay out some, then run the line around the cleat in an attempt to set it (at around 2:1). When I realized what she was doing we agreed to lay out all of the scope first, then set it.
I say this because we've had a Rocna (original), Manson Supreme, and a Rocna Vulcan and never had any issues setting the anchor.
I would look at and consider installing a Mantus swivel. I sounds like something is resisting the anchors ability to roll.
Are we using the transducer depth or the true water depth?
Are we adding the extra 5 feet to the bow pulpit?
20 feet from transducer @ 5:1 = 100 feet
Adding transducer depth (+2.5 ft) and height to bow pulpit (+5 ft)
27.5 feet from pulpit @ 5:1 = 137.5 feet.
What scope when you attempt to set the anchor? We had a lot of trouble when my wife first started. She would wait until the anchor hit the bottom, then would pay out some, then run the line around the cleat in an attempt to set it (at around 2:1). When I realized what she was doing we agreed to lay out all of the scope first, then set it.
I say this because we've had a Rocna (original), Manson Supreme, and a Rocna Vulcan and never had any issues setting the anchor.
I would look at and consider installing a Mantus swivel. I sounds like something is resisting the anchors ability to roll.
did you mean 7.5 feet from pulpit @ 5:1 = 107.5
Do you allow for high tide if setting at low tide.
In some places (particularly in the SE US ) tide is driven by wind. You maybe out of the wind in protected channel but a nearby bay maybe driving a lot of water into that channel. Similarly waves add momentary depth but also shock loads. Hunting increases momentary side loading and shock loading all of which can work an anchor up.
Most charting/nav programs will give you a tide chart with a click. Worthwhile to check for discrepancies.
Agree with Mambo. Much wisdom in his post. More to it than meets the eye. It’s not just using maximum depth from a tide chart and multiplying by 5 then adding a fudge factor. Then add more based on predicted weather.
So what to do? My attitude is there’s no major downside to letting out more. The usual limitation is available space either do to local geography or nearby boats. If I’m not comfortable just go somewhere else. Even if it means anchoring in the dark. Believe like many here before leaving pick a few likely good places to anchor and decide when we get there.
Although we do make a circle looking at depths around the spot we want to drop wife gave me a present I’ve found helpful. A handheld depth meter. You can launch the dinghy and investigate an area before bringing in the mother ship. Better yet find local large rocks or major debris that maybe inside your possible swing.
Also think we are all risk aversive. Ratio depends upon the factors Mambo mentioned but also the consequences of dragging. Think most of us think differently if we’re anchoring in the middle of a wide open bay with mud shores than at the edge of a drop off with a solid rock ledge just past your predicted swing circle. Of course it’s a joke. Where you have the swing dragging isn’t the end of the world. Where you don’t it is. Oh well….
I like our Vulcan. This is no more than an anecdotal sea story, but somewhat of a testament to the Vulcan.
We were anchored in the Bight of Acklins. 10’ deep for miles behind us and no boats anywhere. I set the anchor at 7:1 and dove on it. Looked about half buried so took that as good enough.
That night the winds climbed to 35 knots or so and stayed that way for two days. After it was over I dove the anchor again and took the picture below. We didn’t drag so I figure the current washed away any sand that had been plowed up in front of the anchor when I dove on it initially. Best I can tell we were hanging on the tip only. Vulcan 55 on a 55’ trawler.
View attachment 140091
As some may know we are currently on our Defever 49 in the Aegean Sea (Greece) and that area is known for the Meltemi winds. Normally speaking we would never come here, since Greece does not have an accurate weather forecast, but we have to get to Turkey to install the stabilizers. The Greek weather forecast is basically identical as it was 3000 years ago, in other words, your guess is as good as mine. Sites like Windy, Predict wind etc use the local information to generate nice looking animations, but they have nothing to do with reality.
This Saturday 2 bft was predicted and all of a sudden we found ourselves in 51 kts wind steady. Managed to find an anchorage, which offers a bit of protection, but while I am writing this we still have 40 kts steady 30 degrees off the port bow.
Luckily I have a lot of chain and we threw out 90 mtrs of chain in 4 meter deep water, together with our 50 kg Sarca Excel. We set it well and it holds perfect, also installed a double snubber and two land lines to hold us in place and to keep us with the bow in the waves.
This morning I wanted to know how the anchor had performed through the night. I was pretty amazed to see the first 25 meters of chain (measured from the water line) solid off the bottom of the sea. The next 20 meters was actually still moving and only after that the chain did not move at all. So a scope of 5 : 1 would not have made it. 4 + 3 = 7 x 5 = 35 meters chain would have been an advised scope. The anchor would most certainly been pulled out.
I know I overdid it with more than 12 : 1 scope, but in storms like this I am not taking any chances. 15 meters behind my boat I have the shore which is basically rocks, so I have no room to drag my anchor.
The only problem I have is .................charter boats. The boats that are rented for a week by people who mostly cannot anchor or even cannot sail. They come into the anchorage, don't check where the anchors are, they simply drop their anchor, put out the minimum amount of chain and leave the boat by itself. They are off to shore.
Two hours ago a 40' catamaran showed up, dropped their anchor without asking where my anchor is (missed us by 2 meters) and let out the bare minimum. Now he is lying right in front of my bow. If he starts to drag I have a catamaran on my bow, not looking forward to that and this night the winds are expected to increase to 6 bft (according to the forecast), but we now have the experience that it usually means 1 or 2 bft extra. Wind force 8 with a catamaran on your bow is not a good idea. Going to be a long night again.
This catamaran ahead of us is the latest in a long line of 'idiots on the water', being the charter crews. Last week I had my anchor pulled out 3 times on one day and twice I found a boat hanging on my anchor chain. The skippers completely clueless, even became angry when I called them morons.
Cruising in Europe can be fun, but charter season is horrible and the Meltemi winds make this part of Greece basically a nightmare. We have 14 hours of sailing, in 3 legs, to get to our destination, but it could take over 1 month before we will be able to continue. Whatever happens, we are not leaving this anchorage with wind force 5 or more.
Anyways, long story short. The 5 : 1 scope usually works, but be aware that in strong winds you better throw out as much as you can, it may save you, your boat and whoever is on it. There is no need to risk anything when it is not necessary. But indeed, you need to know how to set an anchor properly and .............having oversized equipment is also not a bad thing. We have a 50 kg Sarca Excel and 140 mtrs of 13 mm chain. According to the books that is too much for our Defever, but we are very happy we have it on board.
. We have a 50 kg Sarca Excel and 140 mtrs of 13 mm chain. According to the books that is too much for our Defever, but we are very happy we have it on board.
Similar experience with a Super Sarca which has a sliding slot in the shank where the pin of a long shackle is inserted. I solved it with an old style swivel between the "U" shackle and the shackle to attach to the chain, it gets the shackle away from the end of the shank so it can`t foul. Common issue it seems, I think Sarca makes a part to do the job.I know this is an old thread but I have had the same experience. I've been boating for 40 yrs and have anchored hundreds of times so my techniques is pretty solid. We bought a new 55 lb Vulcan for our 42 ft trawler for a trip to BC. We had plenty of time so we're anchoring in easy locations.
The first week I took 2-3 tries to get a good set. On every failed set the anchor came up with the shackle hooked crossways around the shank.
I tried different shackles and swivels and still kept getting it jammed.
At a marina then next boat over had the same anchor, I asked if he had trouble and he said not anymore but he did initially.
The problem is the slot in the stick is big and long so the shank can poke through the shackle hoop an jam. His solution was to thread a big zip tie several time through the slot to prevent the shackle sliding down the slot.
shank
I tried it and it worked for me too.