Why Do We Drag Our Anchor?

[Smokeys Kitchen]

Twice on the way up the Inside Passage to Alaska about 4 years ago. I believe both were a combination of poor technique and low scope. ("No - that's all we need honey; nothing's going to happen tonight and no - we don't need to set it that hard").

Tough to explain to the admiral at oh-dark thirty when you are up in skivies on deck ...

Much more methodical and careful since then.

[freshalaska]

My guess most dragging is because the anchor was never set in the first place,
just dropped and never backed down on. I’ve also noticed boats with very very small anchors for what I would think where adequate for the size, weight of the boat.
Also I would think some anchors are dropped with too little a scope, which is maybe okay until it starts to blow.
Most of the posters here are experienced at anchoring but not all boaters have this experience.

[noelex 77]

Originally Posted by Mike OReilly

I'm very curious about this observation Noelex. I don't doubt it's true. Can you say where these areas are, or give some sort of rating for different areas? Are these mostly charter-boat captains? Or are there other generalizations worth noting?

Charter boat skippers are more likely to have poor technique. So in areas with charter boats, the percentage of drags due to poor technique tends to rise. Many charter boat skippers are quite experienced sailors, but often their experience in not with anchoring, so it is quite understandable that their anchor technique is less polished.

We anchor over 300 days a years and have done so for more than than decade, but we still make mistakes. Not surprisingly, I have a lot sympathy for charter boat skippers who get things wrong.

Unfortunately, charter boats also frequently have bad anchoring gear. The skippers are expected to tie up to a marina most nights, especially with a marginal forecast.

Bad anchoring gear makes the skipper look incompetent. Good anchoring gear means most of the time you can get away with mistakes and look like you know what you doing .

[Lodesman]

Originally Posted by thinwater

And yet, "poor bottom" is way ahead in the poll, which surprises no one.

"Poor bottom" is rather subjective, and I think is usually accompanied by another factor. I selected "poor bottom", along with "short scope" and "excessive yawing" which I took as being the closest to "reversing direction due to current". More scope solved the issue, so if I had sufficient scope out to start with, I probably never would have dragged and thought the bottom poor.

[noelex 77]

Originally Posted by thinwater

And yet, "poor bottom" is way ahead in the poll, which surprises no one. I guess I'm fishing for how to quantify or define the most common problem.

The difficulty is that a “poor bottom” really means a “poor bottom for my particular primary anchor”. There are exceptions such as smooth rock where no anchor works, but many of the anchorages that are described as “poor holding” are fine with some of the new generation anchors, at least when oversized.

Anchorages with “poor holding” are sometimes a good choice (although check this reputation is not due to rock) if you have good anchoring gear and are confident that you can hold in the expected conditions.

Anchorages with a notation, or a reputation of “poor holding” are far less likely to be crowded in busy cruising locations, at least overnight, which is always nice. At times of strong wind you need to be more careful, but less crowded anchorages have less risk of other boats dragging into your vessel. So they can sometimes be a sensible choice providing you have good anchoring gear and can therefore take advantage of the increased options.

[Bawlmer]

I anchor in the upper Chesapeake. The one time I dragged anchor was because I did not set it correctly. I just dropped it. Noob mistake that cost me a gelcoat repair. Now I make sure I dig it in in reverse and so far it has held, even through some wind events. I have a standard 13 lb. Danforth.

I checked "other" in the poll because there was not a field for "not setting it correctly in the first place".

[Be Free]

Originally Posted by noelex 77

The difficulty is that a “poor bottom” really means a “poor bottom for my particular primary anchor”.

+1
I voted poor bottom as well. I was using the anchor and scope that would have been appropriate for the bottom I usually find in that area. My anchor was, in fact , totally inappropriate for what was actually below me. I don't think there was a choice for "came in after dark to a new anchorage and used the wrong anchor even though it would have worked perfectly a quarter mile up, down or across the river".

[DMF Sailing]

Never drug, but I used to dive the anchor (Danforth; rode; 7:1; 23' O'Day) in the definitely muddy bottom of Cape Cod Bay. Until one day, I looked up and espied a white shark, got the hell out of there, and never dove again. It turned out to be a harbor porpoise, but what the hell. You tell me you could tell the difference looking up as it swims past you.

[Scorpius]

There are many times it's been a challenge to get the anchor to set (almost always due to poor bottom conditions) but in my 35 years sailing Scorpius I've actually dragged I think four times:
1. Many years ago with a Northill anchor (still quite common on commercial fishing vessels around here). We were anchored on the back side of Catalina Island and, when the current shifted with the tide change, the rode wrapped around the upward-pointing fluke and gently pulled the anchor out of the bottom. We noticed we were drifting and re-anchored without a problem.
2. One night, anchored in a channel in the Chatham Islands off Victoria BC (there's a lovely little cove that I usually anchor in off the channel but somebody was already in there) we anchored with (at that time) our 44# CQR. All seemed fine when we went to bed but the current really rips through there, reversing with the tide every six hours. At 3am I awoke to the sound and feel of Scorpius's stern bumping (fairly gently) against a rock wall. I've never gotten out of bed and on deck faster in my life! We re-set in the dark without difficulty and were up and on our way before the next tide change.
3. I was anchored solidly (again with the CQR) in Porpoise Bay behind Sechelt - a place with good sand bottom and where I had anchored, without issue, many, many times before. I left Scorpius overnight. There was little or no wind and, for this part of the world, very little tide or current there. I returned in the morning and found NO SCORPIUS. I drove (in my car) along the side of the inlet and found her happily anchored off an island three miles away! I hitched a ride on a crew boat taking a work crew to a local hydro-electric plant (I only row my dinghy) and went and got her back and re-anchored. I have no idea why she dragged and drifted, but as I was anchored among some pretty scruffy live-aboards I wonder if perhaps one of my neighbours thought I was too close and, seeing no-one aboard, did something about it.
4.Princess Louisa Inlet: There's places in there where you can tie up to the rock walls and your depthsounder will show no bottom (over 300'). When busy it can be a really tough place to anchor, the few possible places having steep, falling-away bottoms. We tried several times (again with the CQR) and finally thought we were good. We settled down with sun-downers and an hour later realized we had moved out into the inlet in VERY deep water. The rode was hanging straight down from the bow roller. We pulled things up and went and found another area further away from Chatterbox Falls.

It was after that last incident I went and got the 35kg Rocna. No stories to tell with that one (yet!).

[Marathon1150]

Thin sand + volcanic rock underneath + CQR anchor. Very challenging and even diving the anchor to help it find something to hang on to, was only partially successful. Anchor watch was a 24h/d activity in these conditions in the Java Sea.

Local used a grapnel type anchor made from re-bar with all rope rode. This set up worked much better than the CQR plus chain but did a lot of damage to the reef when present. We never anchored on the reef, but on the usually steep wall leading up to it. The grapnels seemed to work well everywhere except in deep sand.

[Simi 60]

Never dragged on our current vessel and we anchor every night for the last 4.5 years.
Have a 150lb Manson supreme and all chain and not afraid to use it.

Dragged on previous vessels and I put it down to not having an anchor windlass.
Not having one had us use borderline sized old design anchors and minimum chain length
Feel pretty sure looking back that with a windlass, we would have had a larger anchor and ran all chain

[DockDoc]

I've never drug yet, I am sure it will happen some day. I use a big Rocna that has to be encouraged off the bow roller on occasion because it is absolutely the largest that fits. I use both engines at 2000 rpm to back down on it, and set a minimum 7 to 1 scope. I've let out 10 to one in bad blows.

"Poor holding conditions" translates to me as "not a suitable anchorage".

I am going to assume, wrongly, that very few sailors continue to use a prior generation anchor (read poor setting CQR and the like) with all the advances that have been made. Would using a CQR fall under gear failure?

[Captain Puget]

The few times I've had a problem was on steep slopes when wind changed and pushed me "down slope". In those conditions I now try to rig a stern line to shore to keep the anchor dug in, but difficult when single handed.

[stinkpots]

I have sailed around the world over a 10 year period and have been mucking about in yachts for over 50 years. I dragged once in the early days when I was a teenager and vowed never to let it happen again, and I have never dragged since.
Blaming any item in the above list is simply avoiding blaming yourself and the poor selection of gear and technique.
If you have the correctly sized gear and if you anchor correctly you will not drag except in exceptional circumstances. I have held in 70 knots even though when we anchored it was calm and we were hit my an unexpected tropical squall, so our standard anchoring system and technique worked.
My gear and method for offshore cruising is as follows.
All chain rode and one size bigger than recommended
A reputable anchor and at least one size bigger than recommended.
Strong windlass to handle heavy gear easily so that if setting anchor is not working you are happy to pick it up and reset easily.
Never less than 5 times depth. I have never been happy with 3 times and only do that for a lunch stop.
With 5 times you have good weight and good none snatching catenary.
Technique is everything. I start by selecting a good spot taking into account, the bottom type, the depth, the possibility of wind direction change, other vessels who may drag etc
Now I start by laying out the first 3 times. Lay it out properly in the direction you will initially sit. Secure it, then slowly back up without force to straighten out chain. Once chain is straight, gently increase engine revs to set the anchor. If it will not hold with a light pull the bottom is poor, move somewhere else.
Once it holds with 3 times let out the full 5 times. Test again with enough revs for a good squall but do not shock load, allow it to take up gently and then slowly increase revs. Gentle and firm!
If the weather is nasty do not hesitate to put out more chain, 8 or 10 times is good. This means I normally choose to anchored in shallower depths, if you anchor deep you will not have enough chain to anchor safely.
Once you get well practiced with this method and do not accept marginal anchor holding during setting you will have confidence it will hold.
However....do not sleep blissfully in bad weather, I always get up in the night to check my holding if it begins to blow.
Happy anchoring!

[thinwater]

Originally Posted by Cheechako

HAH! I had that same problem between Allan's Cay and Leaf Cay in a bit of a different way. One of the few times I put out two anchors (Bahamian Moor) was there. The boat stayed put, but what a mess next am! the 2 rodes were impossibly twisted up. It took a long time next am to sort it out with some chafing on the nylon rode against the chain rode. All my attempts at the infamous Bahamian Moor have turned out similar.

That is what happens if you lay two anchors with the second rode tail in the locker. Don't do it that way.


Instead, have a secondary rope rode on the secondary anchor that is only 50-75' long with an eye on the end, and attach the end of it to the main chain rode on the outside of the roller (locking chain grab or pruisk hitch). When the boat spins, the most you will have to untwist is a few turns with the tail in your hand. The second rode does not have to be chain because:

• Your main rode is chain and that is your back-up.
• The rode will not be yawing, and thus it will not cut. A little chain is good, of course.

I've done this MANY times, up to 15 spins. No problem. Mostly, the single rode absorbs the twists.