Anchoring Technique - Three Questions

[mvweebles]

.... For example, I do not free-fall the anchor and chain. That much mass flying through the chain locker, deck plate, windlass, foredeck, and bow roller just gives me the willies. It seems like a bad accident waiting to happen..

Did the Morgan's Child article recommend free fall release of anchor rode? Chain? If so, that's counter to anything I've ever read. The only justification I can think of is happy hour was about to end.

Peter

 

[twistedtree]

Did the Morgan's Child article recommend free fall release of anchor rode? Chain? If so, that's counter to anything I've ever read. The only justification I can think of is happy hour was about to end.

Peter

I though so, but I only skimmed the article.


I think people do it to get the anchor on the bottom before the boat drifts much from their chosen location, which is especially important if you mark an anchor watch before dropping the anchor.


I address this another way by pre-deploying the anchor to within about 10 feet of the bottom, then dropping the last 10' once I'm on mark. So if it's 40' deep, as I'm working myself into final position, I'll start dropping the anchor down to about 30', then stop. Once in final position, I'll continue dropping and the anchor will be on the bottom before the boat can move very far. This works well for me, especially when it's 100' or more deep.

 

[Jeff F]

I understand that, but 4:1 in 10' of water isn't the same as 4:1 in a 100' of water. With an all chain road, for the same wind or current, what snaps a 40' chain straight isn't going to significantly modify the curve of 400' of chain. End result is the 40' is lifting the anchor's draw bar up, when the 400' still has chain laying on the seabed.



Ted

I should say that your description of how you anchor matches mine pretty much exactly. And we have very similar vessels and ground tackle. I have a 73 lb Rocna and 250' of 3/8 chain.

But I'm going to disagree on scope. My standard these days is 3:1. I measure out the chain until the anchor hits bottom, then add 2x more. I can't remember dragging any time with this standard. I increase scope in a blow - up to about 5x if I have lots of room - but have zero concern at 4-5x scope if I'm in a decent anchorage. The only time I've reached the end of my chain was when I had it out to measure and mark.

Obviously there is no harm in more scope, but I don't think it's a requirement for fair weather anchoring.

I was thinking of catenary curves coming across the lake just now. I'd be curious to know the force require to get the chain off the bottom at various scopes.

 

[Jeff F]

So if it's 40' deep, as I'm working myself into final position, I'll start dropping the anchor down to about 30', then stop. Once in final position, I'll continue dropping and the anchor will be on the bottom before the boat can move very far. This works well for me, especially when it's 100' or more deep.

That makes sense. I guess if you're not moving fast and hover long enough to allow the rode to go vertical you can choose and mark your anchor drop position very well.

Far too much precision for me

 

[psneeld]

I should say that your description of how you anchor matches mine pretty much exactly. And we have very similar vessels and ground tackle. I have a 73 lb Rocna and 250' of 3/8 chain.

But I'm going to disagree on scope. My standard these days is 3:1. I measure out the chain until the anchor hits bottom, then add 2x more. I can't remember dragging any time with this standard. I increase scope in a blow - up to about 5x if I have lots of room - but have zero concern at 4-5x scope if I'm in a decent anchorage. The only time I've reached the end of my chain was when I had it out to measure and mark.

Obviously there is no harm in more scope, but I don't think it's a requirement for fair weather anchoring.

I was thinking of catenary curves coming across the lake just now. I'd be curious to know the force require to get the chain off the bottom at various scopes.

Not pointing the finger at everyone participating, but some feel there is no such thing as fair weather anchoring. Every time it is for a Cat 2 hurricane.

I will admit if not good at weather, then maybe not a bad idea to always anchor like your life depends on it.

 

[mvweebles]

Not pointing the finger at everyone participating, but some feel there is no such thing as fair weather anchoring. Every time it is for a Cat 2 hurricane.

I will admit if not good at weather, then maybe not a bad idea to always anchor like your life depends on it.

Ted speculated I had "CQR Syndrome." Between this post and his, there's a nugget of truth. Much of my early anchoring was San Francisco Bay (and yes, I came of age when a CQR was the modern anchor).

Many anchorages in SF Bay are subject to harsh currents - 3-kt ebb is not uncommon. And of course the current reverses. You learn a couple things. First, as good as a Danforth is in sticky mud, it's subject to fouling on a 180 reverse. Second, if you want your boat to stick, setting the anchor is a good predictor. That said, SF Bay is generally good holding with the sticky, stinky grey/black mud they comes up.

My wife and I have a routine for anchoring that includes a relatively light power set to assure secure anchor attachment that isn't too different than the consensus in the latter part of this thread. We don't use headsets so we just follow our protocol and use hand signals (we tried headsets but found them distracting). When we've anchored in a river, we'll set a stern anchor but that's a different thread altogether. But for the most part, we follow a stepwise pattern that culminates in a power set.

That's how we roll. So far so good.

Peter

 

[Jeff F]

...(and yes, I came of age when a CQR was the modern anchor).

You must unlearn what you've learned. Unless you still use a CQR.

 

[Hippocampus]

Not pointing the finger at everyone participating, but some feel there is no such thing as fair weather anchoring. Every time it is for a Cat 2 hurricane.

I will admit if not good at weather, then maybe not a bad idea to always anchor like your life depends on it.

There’s a diversity of folks here. Many here could and have been able to carry on a decent back and forth with Chesneau, Parker or the folks from Commander’s . Some have even taught others. Some have reason to be fairly secure about weather. But never say never. Beyond outlying weather events unusual events occur.
As said above if situation allows I like 5:1 as the go to with twin snubbers. Doesn’t take more time. Having done such then retired for the evening on the north side of Rodney Bay.there was the infamous north swell running so tucked in to shore and went further into the bay than usual. Typical winds for kite season. We were on a 46’ sail. A mid 50s FD power was to our starboard aft quarter. During the night an unexpected white squall caused him to drag as the wind flipped 180. We woke up. On getting on deck he asked if he could throw us a line. He did and together further secured him to prevent him from going on the rocks. We were both single handed. Wives having flown home. Event lasted maybe 20 minutes total. Prior he had tried to pull in his anchor but it had set on he thought short scope. We both decided to stay put with engines in neutral monitoring events which worked out well.
Neither he nor I expected the event. Nor did either of our weather services. Nor did downloaded data suggest this risk. Given after the event and his departure we were closer to shore than I liked moved.
Shortly after resumed our prior N facing position.
So have no hubris about boat decisions. See little downside to being prudent. Doesn’t require extra effort. Don’t consider myself infallible. Don’t consider weather predictions infallible. Think believing you’re always right increases risk. Fair weather may not always remain and the change may not be predictable.
Yes my technique was well below that I use for storms but is well above lackadaisical. All decisions ultimately are risk/benefit. Here always having good thoughtful technique has little or no downside and in this event had a considerable upside.

 

[mvweebles]

You must unlearn what you've learned. Unless you still use a CQR.

As I said upthread, 25kg Vulcan and a Mantus M2 and a Fortress in the hole. I went to a Bruce after the CQR, then a Delta. With a Danforth in the hole.

I still don't see the downside of power-setting. Way upthread i included a picture of a chart that shows an anchorage. The chart says it's an anchorage. A half dozen attempts to power set says it's a flooded tarmac. That's a tough lesson to unlearn, but I wish you well. Better still, I wish those downwind of you well.

Peter

 

[Hippocampus]

As I said upthread, 25kg Vulcan and a Mantus M2 and a Fortress in the hole. I went to a Bruce after the CQR, then a Delta. With a Danforth in the hole.

I still don't see the downside of power-setting. Way upthread i included a picture of a chart that shows an anchorage. The chart says it's an anchorage. A half dozen attempts to power set says it's a flooded tarmac. That's a tough lesson to unlearn, but I wish you well. Better still, I wish those downwind of you well.

Peter

Peter what do you do in loose mud and soup? Do you wait before the power set? If so how long?
Totally agree marked anchorages are a suggestion. Would further say many great anchorages aren’t marked as such at all.

 

[psneeld]

Yep, I am lacksidasical,, and full of hubris ......so have fun....carry on.

 

[Jeff F]

Better still, I wish those downwind of you well.

I guess I should have ended my post with an emoji [emoji17]. No offence meant. It was meant to be light hearted.

My AIS list is empty right now, and that's the way I like it. If I engage in risky behaviour it's on me alone.

 

[Hippocampus]

Peter I seriously doubt you engage in risky behavior. I doubt PS did either. I prefer to believe you both consider risk benefit and both take the modest extra step to decrease risk. As you say don’t see any downside to assuming fair weather will always persist.

 

[mvweebles]

Peter what do you do in loose mud and soup? Do you wait before the power set? If so how long?
Totally agree marked anchorages are a suggestion. Would further say many great anchorages aren’t marked as such at all.

I haven't encountered soup yet so I don't know.

I can tell you I'd have a hard time sleeping if I just dropped an anchor and didn't challenge the hold. So I'd look to others for guidance. Best I can tell is the theory is the anchor (and rode) slowly sinks through the ooze until it finds something toothy. 15-mins for a light power set? How do others do it, with emphasis in cruisers who carry liability-only insurance?

Peter

 

[mvweebles]

Peter I seriously doubt you engage in risky behavior. I doubt PS did either. I prefer to believe you both consider risk benefit and both take the modest extra step to decrease risk. As you say don’t see any downside to assuming fair weather will always persist.

I'm not immune to risks. Like anything in life, it's a calculation of probability (weather knowledge helps) and impact weighed against mitigation effort.

The probability and impact of dragging anchor varies, but the mediation effort - strong ground tackle and technique, which for me includes challenging the bite - is very low. Which is why I say why not power set? Only takes a minute or two.

In my previous post I confessed to having no experience with soup. Suppose I found myself in the Chesapeake without prior knowledge of the bottom. I'd try my standard technique of power setting and fail miserably. Eventually I'd figure something out, but I'd be on the safe side of the equation, albeit searching for a safe place.

Now, take the opposite - a person who was used to just dropping anchor without much thought. Suppose they suddenly found themselves in Whalers Cove, the tarmac-bottom anchorage near Pebble Beach I've mentioned a couple times in this thread. They'd drop anchor and call it a day without knowing nothing is holding them except shear weight of anchor and rode.

Seems so simple. Spend a couple of minutes to challenge the bottom and sleep well.

Peter

 

[Hippocampus]

So far pretty much as you say. In light air use engine (thrusters) to lay out the rode in the direction we think we will lie and wait and wait and wait. Usually with the engine off after cool down. Then before bed depending upon expected weather, prior experience in that area may check the set.
In any kind of decent wind or current again use the engine to lay out chain but with forward not reverse. If drift back is fast and strong may use the engine to slow drift. A constant pull may give you a furrow. But here may not power set. It often just pulls the anchor out. Typically when cruising we have several hours before we go to sleep so easy to monitor. Same if we go off exploring. Generally leave the boat in the morning so have a whole night to see if drift occurred. Tend to change our habit’s depending upon where we are. Very conservative about leaving the boat when in loose mud. Want a suitable interval first (hours under some degree of wind or current load) or yes will check with a run in low idle reverse after a long wait.
Problem I have in mud is we use chain. Chain produces a decent amount of drag if resting in the mud. In light currents or wind the chain not the anchor maybe holding you in place. Might even prevent swing or slow it down a lot. Agree with you you don’t know the set of the anchor unless the chain is pulled fairly tight. Agree with PS you don’t get cat 2 every night. But we’re usually in the chessie during shoulder seasons so do see T storms even occasionally when not predicted. So do back down on occasion. But gently and usually only enough to tension the chain. Definitely try to have open water in the direction we might drag. Unfortunately there’s some places and times the wife feels an anchor watch is justified. I’m secure with the electronics doing that job. She’s more a nervous nelly and she’s not wrong either. Think whatever you do have a set up where moving or resetting isn’t a big deal. It happens very rarely but seemingly always when you don’t want to do it. Do like the mantus chain hook. The old style more than the current one.

 

[Hippocampus]

In my previous post I confessed to having no experience with soup. Suppose I found myself in the Chesapeake without prior knowledge of the bottom. I'd try my standard technique of power setting and fail miserably. Eventually I'd figure something out, but I'd be on the safe side of the equation, albeit searching for a safe place.

Peter and PS think this supports my point. With different places, conditions and boats you should modify your technique. It’s prudent to not assume fair weather will always remain such and accept occasionally you will be mislead. Sure be reasonable and yes being alive means you’re assuming risk. Just saying play the odds and to a reasonable extent work them in your favor.
Mud, ledge, anchorages (like Newport) where cable and debris has been dumped for hundreds and hundreds of years are examples where prepping for cat 2 can increased your risk. If you have to move or you drag getting free is going to take longer. Just asking people play what if before anchoring and not be dogmatic.

 

[Simi 60]

Not pointing the finger at everyone participating, but some feel there is no such thing as fair weather anchoring. Every time it is for a Cat 2 hurricane.

I will admit if not good at weather, then maybe not a bad idea to always anchor like your life depends on it.

Goes along with "chain does nothing for you sitting in a locker"
I paid good coin for it, I'm going to use it.

 

[O C Diver]

I should say that your description of how you anchor matches mine pretty much exactly. And we have very similar vessels and ground tackle. I have a 73 lb Rocna and 250' of 3/8 chain.

But I'm going to disagree on scope. My standard these days is 3:1. I measure out the chain until the anchor hits bottom, then add 2x more. I can't remember dragging any time with this standard. I increase scope in a blow - up to about 5x if I have lots of room - but have zero concern at 4-5x scope if I'm in a decent anchorage. The only time I've reached the end of my chain was when I had it out to measure and mark.

Obviously there is no harm in more scope, but I don't think it's a requirement for fair weather anchoring.

I was thinking of catenary curves coming across the lake just now. I'd be curious to know the force require to get the chain off the bottom at various scopes.

So when you anchor in 8' of water, 24' of chain, half your boat's length, is what makes you sleep well at night. Good to know.

Something like 90 to 95% of my anchoring is in 20' of water or less. As I go deeper I use less scope. Just can't fathom why 24' (3:1 @ 8') is such an important savings over 56' (7:1 @ 8').

Ted

 

[Hippocampus]

Guess I think a little bit differently about this. At these shallow depths there’s very little chain out. Although I routinely use twin snubbers I don’t routinely use a kellet. Find kellets a pain to set up and retrieve. So I like chain weight to serve as a catenary .
Therefore although anchor commonly in 10-20’ now we are coastal east coast still like around 75-100’ out even when less would give 5:1. Willing to hose off chain as it comes up.
The issue is whether you have too little chain out. Rarely it’s do you have too much.

 

[rslifkin]

I don't understand the power setting will just pull the anchor out thing. If it won't hold at least idle reverse, then it's not going to hold if the wind comes up. The only time I had the anchor start to set as I gently brought up tension on the rode (boat slowly drifting back) and then break free as the rode stretched in idle reverse, it turned out we had found a patch of cobblestone that provided very little holding. It held us during the day in 10 kts of breeze, but if it had come up to 25 - 30 we certainly would have been dragging (and I wouldn't have stayed there overnight as a result).

 

[O C Diver]

I don't understand the power setting will just pull the anchor out thing. If it won't hold at least idle reverse, then it's not going to hold if the wind comes up.

Ok, for my boat it's a visual indicator. When I back up, jogging the transmission in and out of reverse, 90' of chain will go straight taunt when the anchor starts digging in. It takes around 30 knots of wind to accomplish the same thing. Staying in reverse, the boat moves faster and the shock load is a multiple greater. If I'm anchoring for 60 knot winds, there's a significantly greater scope (chain length) and the snubber is many times longer to handle substantially greater shock loads as it stretches way more.

Ted

 

[Hippocampus]

Think this refers to a vey specific set of circumstances. Soup, then loose mud, then firm mud. In all the anchor tests pretty much all the nextgen do poorly in this stuff. They plop down and trap enough loose mud between the flukes to nearly float on the stuff. Over time it oozes out the back and establishes its good orientation. Eventually it reaches the firm mud if you wait long enough. At that point the tip buries in the firm mud and mild sustained tension pulls it deeper into the firm mud. But if you pull on it too early or to hard they just skate along under the soup and between the loose mud and firm. At least that’s how it was explained to me.
This set up is seen in the Chessie but also in spots along the coast of Mass Bay. I switched practice. Either going to a Fortress or just waiting. before applying tension. Interestingly if you get down to firm mud it’s great holding in my experience. These anchors will continue to work their way down. Will even have troubles getting them up after being in the same spot for awhile. Needing a bit of chop when up and down or running over them a bit. Either lets you work them back up incrementally until free.
Haven’t been using an anchor indicator float (that may change). But was taught a trick that sometimes works if you have a dinghy with a strong engine (currently have a 40hp). If stuck under/between rock or an edge of rock ledge and even cable attach a line as deep and far away from the boat to the stern of the dinghy as you can.
Using the dinghy engine pull the chain backwards and to the sides. Try different angles. Use the main engine(s) on the mothership so there’s no tension on the chain between it and the dinghy. In warm clear waters just dive the anchor to attach line to the anchors back. But in cold murky waters this trick may save the cost of a diver. We don’t carry tanks or a dry suit but can pull ourselves down the anchor chain if it isn’t too deep.Still won’t do that in Maine.
Think Teds been there done that and has the t shirt. Just wait longer in soup/loose mud before any tension. Find staying in reverse too early results in the anchor pulling out.

 

[rslifkin]

Ok, for my boat it's a visual indicator. When I back up, jogging the transmission in and out of reverse, 90' of chain will go straight taunt when the anchor starts digging in. It takes around 30 knots of wind to accomplish the same thing. Staying in reverse, the boat moves faster and the shock load is a multiple greater. If I'm anchoring for 60 knot winds, there's a significantly greater scope (chain length) and the snubber is many times longer to handle substantially greater shock loads as it stretches way more.

Ted

That sounds like the right way to do it and it's pretty close to what I do. I don't stay in reverse and go flying backwards, expecting the anchor to stop the boat. I gently move the boat backwards to slowly bring up tension as you described. Once the rode is stretched and going tight, then the engines go in reverse and stay there to apply a steady load without yanking on the anchor with the weight of the boat.

 

[Jeff F]

So when you anchor in 8' of water, 24' of chain, half your boat's length, is what makes you sleep well at night. Good to know.

Well, not quite. In 8' of water my anchor roller is about 15' above the bottom. In practice I'll set with 45-50' of chain out, and have come to expect an instant set and reliable holding in the conditions I'm typically in.

If conditions are challenging or unsettled I'll increase scope. Have rode out a couple of tropical storms (~50 kt sustained) with 5-6x scope and felt secure.

I'm not trying to tell others what to do, only sharing my experience. My motivation for experimenting with shorter scope comes out of my preference for anchoring in close to shore whenever possible, and often I'm on rivers and waterways with limited swing room. With 50' of chain out I have a swing radius of about 100'.

 

[O C Diver]

Well, not quite. In 8' of water my anchor roller is about 15' above the bottom. In practice I'll set with 45-50' of chain out, and have come to expect an instant set and reliable holding in the conditions I'm typically in.

Generally, scope is the ratio of chain length in the water in relationship to depth when the chain is taunt.

Is there a snubber in your equation that changes the ratio,?

Ted

 

[Hippocampus]

Jeff think this gets back to what you get out of increased scope.
Changes the angle of pull.
Increases amount and weight of chain.

But in sustained heavy winds think the chain is always tensioned enough it’s tight enough to walk on. Think only the snubbers are mitigating shock loads to any appreciable degree. So the catenary effect of a lot of chain may not amount to much benefit.
Do think in waves more scope means the angle changes less. Do think this helps prevents the anchor from slowly working out.
Don’t think increasing scope helps much in decreasing the angle change if you’re skating. Do think side to side is as bad as up and down. So do use the technique outlined in Attainable Adventures (Morgan cloud) to prevent hunting.
Still you get back to the angle between the chain and the bottom. How much does this really matter once the angle is low enough for the anchor to continue to dig. Think that depends on which anchor, how high the waves are, and how high and rapidly your boat rises to a wave. Have wondered with the next gens how much more holding do you really get out of going more than 7:1 and is 5:1 adequate for up to strong gale conditions. Also think 5:1 in deep water is different than 5:1 in skinny water. Thoughts?

 

[C lectric]

Wow, lots of advice. I will add simply what we do. We have a Rocna anchor.

We line up facing the wind direction.
If we are anchoring in 40' of water then while sitting I lay out about 45' of rode. Not enough to foul the anchor, at least not yet.
Hand signals get my wife to reverse throttle at idle and I lay out 120' or more of rode. Minimum about 3X depth.
I watch the rode and get her to go out of gear and let the boat drift back untill I see the boat slow and the rode lift a bit.
THen back into reverse to snug the chain more for another chain lift only more so.
Then out of gear again so the boat can drift forward and slacken the chain.
THe reverse again but in and out so I jerk the rode minimally.
Then I ask for reverse as soon as the boat start to go forward from the chain weight. THis time She stays in reverse and I look for landmarks to sight on, trees in line, rocks in line, logs stranded in line or close enough in line to be a good sight. Almost always that is enough. Once in a while I need to lay out four time the depth but seldom.
If there is any question about the bottom I will get her to to raise the revs to about 1,000 which is a lot of pull for about 20 sec. If still no movement we shut down and make any further adjustments to rode length for tide changes as needed out to about 4:1 and add the snubber line.

Yes, once in a while I can hear the anchor skating across a rocky bottom. If I cannot find a decent spot without the rock then we move.

Of course I watch that I am not crowding another boat in which case we also move.

 

[O C Diver]

Also think 5:1 in deep water is different than 5:1 in skinny water. Thoughts?

Unquestionably there's a difference. In 10' of water there is around the weight of 50' of chain to lift and straighten out. In 100' of water there's around the weight of 500' of chain to lift and straighten out. Up to a point, the weight of 500' of chain becomes the snubber. It takes substantially less wind to lift and straighten out 50'

Ted

 

[O C Diver]

Wow, lots of advice. I will add simply what we do. We have a Rocna anchor.

We line up facing the wind direction.
If we are anchoring in 40' of water then while sitting I lay out about 45' of rode. Not enough to foul the anchor, at least not yet.
Hand signals get my wife to reverse throttle at idle and I lay out 120' or more of rode. Minimum about 3X depth.
I watch the rode and get her to go out of gear and let the boat drift back untill I see the boat slow and the rode lift a bit.
THen back into reverse to snug the chain more for another chain lift only more so.
Then out of gear again so the boat can drift forward and slacken the chain.
THe reverse again but in and out so I jerk the rode minimally.
Then I ask for reverse as soon as the boat start to go forward from the chain weight. THis time She stays in reverse and I look for landmarks to sight on, trees in line, rocks in line, logs stranded in line or close enough in line to be a good sight. Almost always that is enough. Once in a while I need to lay out four time the depth but seldom.
If there is any question about the bottom I will get her to to raise the revs to about 1,000 which is a lot of pull for about 20 sec. If still no movement we shut down and make any further adjustments to rode length for tide changes as needed out to about 4:1 and add the snubber line.

Yes, once in a while I can hear the anchor skating across a rocky bottom. If I cannot find a decent spot without the rock then we move.

Of course I watch that I am not crowding another boat in which case we also move.

I'm curious what size chain are you using? This is for the Palmer 32'?

Ted