Anchoring and shifting winds

Hi all, this may be a silly question here but.... I’m mostly a day tripper and always watch my ‘spot’. We have been doing more and more overnights on the hook especially recently with lockdowns. Typically I set my anchor and in the crowded areas I sometime frequent will use a 3:1 scope to limit swing. For an overnight I’ll put out closer to 4:1 or even 5:1 depending on the forecast (typical anchorages in these parts are 10-20 ft depths). But I get a lot more swing of course, especially if the wind shifts. I have all chain rode on my ‘40 Hatteras.

The question....when a wind shift occurs, say a 180 deg shift over night isn’t uncommon, does anyone ever pull up and reset the anchor? Seems like if the anchor is set in one direction, a 180 shift could facilitate the release of the anchor, no?

Not if you have a modern anchor: it will just reset on its own.

I would also go 7:1 for your overnight and use a snubber.

With most modern designs of anchors (and some older ones too), assuming the anchor is large enough and you have appropriate scope out, a wind shift shouldn't be a problem. It's only likely to cause any real trouble if there's stuff on the bottom (weeds, etc.) that could foul the anchor if it does pull out and need to reset AND you get a fast / violent shift that causes it to break free rather than just shuffling around in the bottom.

Personally, I tend not to worry about it.

I didn't use to worry about. I have a modern anchor (44lb Rocna Vulcan) with all chain at 5:1 and have not had an issue. However this past weekend the wind shifted, then picked up to 30-40. When I woke up on sat. morning the snubbers were creaking, however I found we had slid back about 2 boat lengths or more. We appeared to be holding. 30 minutes later we dragged into the mooring field.

My neighbor picked up and reset for the direction of the predicted blow. He was fine.

Hi Shrew, where was that?

"Modern" anchors don't necessarily do better at this. The CQR, for instance was designed specifically to address this issue way back in the day.

A well set anchor of about any description will hold most if not all of the time; very liquified bottoms can be problematic especially if you haven't been able to take the time let the anchor sink deeply.

A good practice is to leave your chartplotter on with the track active. This and simply observing how your boat reacts to various forces on it are very useful. Definitely use a snubber of some sort (many threads on this subject here) to take shock loads off the chain and windlass.

I've anchored in clocking winds or current (often over the course of several days in the same spot) with a Danforth HT, various CQRs, and probably a few hundred times with a Delta.

There are many factors to consider when it comes to anchoring. All chain rode with a good snubber is a good start to improve holding when compared to the same scope of mostly rope. Is your anchor sized correctly for your boat (size, model, windage, etc.)?
What is the bottom material? Sticky mud is good. Heavy weeds, rocks, or thin precipitated material not so good. What anchor are you using? Some have a very good reputation, others, not so much.
However, if you have a good anchor, use adequate scope (if anticipating shifting winds or higher winds, I use no less than 5-1 scope at the high tide mark), and are anchoring in a good sea bed type for anchoring, and set your anchor well, you should not have to "re-anchor" due to a normal wind shift.
Pay attention to what is happening around you during the day (how your boat is reacting), set an anchor alarm, monitor your plotter, etc. and if you hear the wind build in the night, maybe get up and check things out.
JMHO and what I have found has worked for me over the last 16 years of anchoring out about 50 nights per year (average).

Why do you limit the scope so much?

caltexflanc said:

Hi Shrew, where was that?

Click to expand...

Great Salt Pond (New Harbor) on Block Island, RI. Ironically a place where I've contested, many times (despite a large number of reported and personally witnessed dragging incidents), has good holding in mostly sand and shells.

I had initially set the anchor, backing down to 1200 rpm. I was at 5:1 and had been there for 9 nights. Including 3 of those nights with a Mainship rafted up to me in a 20-25 kts.

We were dumbfounded as we tend to anchor out around 50 nights per season.

Shrew,
That situation does sound very unusual!! We have a Vulcan as well, and have not dragged (yet ).
I too would be very surprised after 9 nights (anchor soaked in) and having also had a "raft" earlier in decent winds.
Hard to explain, I would say.

To the OP:
I overnight a lot in many different spots. Less than 20' of depth, it's 7:1 all chain rode. A good anchor drag alarm is also important. You didn't mention what anchor type and size you're using. Make sure it's adequate or oversize for your boat. I've never dragged on a reverse wind or current situation, but then I have chain on the seabed in front of the anchor.

Ted

Thanks everyone...interesting reads all around. Biggest takeaways are to worry less, put out more scope with snubber, and keep watch electronically or otherwise. I have a Bruce anchor but am not sure of the size, so am adding a little research into the mix as well. Thanks! Stay safe.

Well...correction....I think,it’s a Delta anchor? Will verify later today. Trying to submit a pic.

We have dragged our 44# Rocna Vulcan 3 times.
Two times in North Carolina and once in South Carolina. Two of the times were TS microburst conditions in soft muck bottom and one was in prolonged 20-40 knots NE for a day in mud. To its credit, on the last one, it did catch again while trying to retrieve. It broke the windlass but the anchor held with short scope until the wind died the next morning. We did not have any problems until added a full FB enclosure. We should have upsized to 55#.

High Wire said:

We have dragged our 44# Rocna Vulcan 3 times.
Two times in North Carolina and once in South Carolina. Two of the times were TS microburst conditions in muck bottom and one was in prolonged 20-40 knots NE for a day in mud. To its credit, on the last one, it did catch again while trying to retrieve. It broke the windlass but the anchor held with short scope until the wind died the next morning. We did not have any problems until added a full FB enclosure. We should have upsized to 55#.

Click to expand...

Your experience is part of what pushed me to buy the 73 lb Vulcan rather than the 55. I've got no more windage than you do, so the 55 would have probably been enough, but I wanted "definitely enough" and we do get some ugly thunderstorms that come up out of nowhere with little warning around here this time of year.

I've been anchoring for 40+ years. I very rarely had issues with the anchor not re-setting with a wind change. For most of those years we used a Danforth type, our biggest problem after wind was getting it free from the bottom. We now use a Bruce on our current boat, so far also no problem with shifting winds. That said I normally us more than 3:1 (especially with the Danforth).

In the few cases where it would not reset it was generally due to things like eel grass getting caught up in the flukes, meaning if you do drag you have to pull up and check as to why. But if it's holding, leave well enough alone.

Measuring the anchor I have I’ve determined it’s a 35# Delta. (They’re good about putting dimensions into a handy spec sheet). Sounds like from the combined wisdom my 40’ Hatt likely needs a much heavier anchor if I’m to continue more overnights with a better peace of mind. It’s a great day anchor and hasn’t failed me in the five years I’ve had the boat.
That being said....kudos to this blog and all responders herein. I’m a relative newbie to the size and type of boating here, so believe me when I say that all the banter and tips serves me and I’m sure many others well. Thanks again.

Check out the sizing guide of whatever brand of anchor you decide to upsize to, but I would guess (only a guess), that due to your boat size and especially the windage you present, that you will need at least a 55 lb. (25 kg) anchor, especially since you seem to go with shorter scope. Now, will your bowsprit and roller, as well as windlass accommodate that? I have seen many Vulcans fit that type of bowsprit?
Good luck.

When I bought the 40 Albin it had a 33 Delta and it simply was not reliable.
Went to a 44 (next size up) and that held fine.
But since I'm a Danforth fan, I found a nice used 35 high tensile and never dragged with that on all chain, usually at approximately 10:1 scope.
Been in many wind/tide reversals and it held.

We have anchored 30+ times this year and use greater than 3:1 scope and have anchor watch, plus I log our lat/long position. Only up to 25-30kt gusts and what I've found is even with opposite wind direction change, our all chain rode keeps us in the same relative position to the anchor. Meaning we haven't swung beyond the original anchor position, the boat rotates around the chain lying on the seabed.


I'm sure with heavier sustain winds we would eventually float past the anchor and then I would make sure it resets. Of course I would need to pay close attention to the winds and be sure to be onboard.

JHeide,
Have you seen “Anchor Setting Videos” .. a thread here on TF. Has 600 replies. He found a slotted or holed (ventilated ?) anchor to clog much dramatically less. The same anchor would clog consistently w/o holes in the fluke and he couldn’t make it clog with the holes installed. See the Vids. If I had to depend on reversals I’d get the SARCA, an Australian product and I’d leave the shackle slot open to work as designed.

I am not sure the mud clogging is an absolute repeatable event preventing resets.

Many Rocna and Manson Supreme owners anchor in muddy areas with strong tide reversals and don't seem to have issues.

Where I boat, we can have some significant tidal current changes. With a modern anchor, it has not been a problem. With a really well set CQR, I didn’t have any problems either.

I had an experience a couple years ago where I had an engine failure in the Tacoma Narrows. I drifted closer and closer to the steep sided bank and finally put my Sarca Excel down. The Sarca Excel grabbed and kept us off the hard. However, we were at the border of current eddy. The eddy would first push us North, then South. Each time the anchor would reset itself. Granted, each time we also moved few feet closer to shore, but I was really impressed by the performance. After going through that, I no longer worry about normal tidal and wind changes when at anchor.

Dave,
I think mostly the Excel sheds the mud because of it’s fluke shape. But I’ll bet the cutouts reduce/prevent plugging where the flukes flip up and out.

Re the question about limited scope. In the PNW (or PSW for our British Columbia friends), we have a lot of deep anchorages and a lot of crowded anchorages. When you are in a 50 foot deep spot, with a 10-15 foot tidal swing, you can end up with a pretty big circle at low tide!

My personal limit is 100 foot deep. At that depth, I put out about 250 to 275 feet of chain (I have total of 300 feet). At 5 to 1 or 7 to 1, it would require an enormous amount of chain and the swing circle would be pretty big.

All-chain rode and a big anchor seems to work for my boat, even with limited scope

Spinner said:

Re the question about limited scope. In the PNW (or PSW for our British Columbia friends), we have a lot of deep anchorages and a lot of crowded anchorages. When you are in a 50 foot deep spot, with a 10-15 foot tidal swing, you can end up with a pretty big circle at low tide!

My personal limit is 100 foot deep. At that depth, I put out about 250 to 275 feet of chain (I have total of 300 feet). At 5 to 1 or 7 to 1, it would require an enormous amount of chain and the swing circle would be pretty big.

All-chain rode and a big anchor seems to work for my boat, even with limited scope

Click to expand...

I believe this is when you move from relying less on the anchor itself to relying more on the overall weight of the ground tackle you have put out.

Spinner said:

Re the question about limited scope. In the PNW (or PSW for our British Columbia friends), we have a lot of deep anchorages and a lot of crowded anchorages. When you are in a 50 foot deep spot, with a 10-15 foot tidal swing, you can end up with a pretty big circle at low tide!

My personal limit is 100 foot deep. At that depth, I put out about 250 to 275 feet of chain (I have total of 300 feet). At 5 to 1 or 7 to 1, it would require an enormous amount of chain and the swing circle would be pretty big.

All-chain rode and a big anchor seems to work for my boat, even with limited scope

Click to expand...

Anchor experts seem to all agree that total length of chain put out is important whether in 10 or 100 feet of water. Thus the higher ratios for shallower water.

I am a sturgeon angler and California Delta gunkholer. I would typically head out fishing for 3-5 days at a time. I might anchor 5 times per day...and then again, sometimes one. When I cruise, it can be from every day re-anchoring to staying put for a couple weeks. My first 130 ft is chain so I can easily single-finger my anchor down and up in depths of 20-30 ft.

I've learned to try to anchor in depths that are a balance of adequate wind protection, tidal/current protection, sufficient depth to set the hook without weeds and allow sufficient swing. Sometimes, I use a stern anchor or two.

I listen to my boat while I sleep and get tired of false alarms with anchor alarms.

Preventing anchor pullout in shifing winds

Set two anchors in a straight line using two seperate rodes with the boat in the middle and both roads connected at the bow. Expect some twisting.

Mike Negley said:

Set two anchors in a straight line using two seperate rodes with the boat in the middle and both roads connected at the bow. Expect some twisting.

Click to expand...

You want to anchor in a Y fashion?

I vote for one anchor off the bow and one anchor off the stern.