Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-15-2017, 10:44 AM   #1
Senior Member
 
Montenido's Avatar
 
City: La Paz, BCS
Country: Mexico
Vessel Name: Ansedonia
Vessel Model: Californian/Carver 52CPMY
Join Date: Dec 2014
Posts: 300
Anchor Dragging Story (long)

Hi folks,
I just returned from a lengthy stay in Mexico, some aboard my boat, and some aboard another boat. I had a very scary anchor dragging incident that I thought I would share. I was anchored with my wife in the south end of a place called "The Hook", on Isla San Francisco, in Baja. We anchored in calm conditions in about 12' on a sandy bottom. For tackle I had a new Manson Supreme 45# on 5/16 chain. I had about 100' of rode out, with 20' snubbers.

This particular spot normally has no waves due to being in the Sea of Cortez. No swell influence, although wind can change that. At this time of year northern winds are the norm, but we were experiencing a southern blow, so I was sheltered from that direction by the point. Anyway, the wind started to build around midnight, and was blowing a full gale within an hour or so. I got up to check on things at about 1:30am and all looked okay. About an hour later I was awakened by the sound of surf breaking on the beach. I looked out the rear port window and saw dry sand about 15' behind my transom! I yelled for my wife to wake up, started the engines, and turned on the windlass.

Fortunately, it was a full moon, so there was some night visibility. In the normally calm bay there were breaking waves across its whole width. Since I was worried that we might already be on the bottom, I used the windlass to pull us into deeper water. As soon as I felt that it was safe, I had my wife put both motors in forward and idle into the waves, while I retrieved our rode. Once we were clear, we motored to the mouth of the small bay and had a chat. It was too rough to head out, so we opted to drop the anchor in about 20' and let out 150" of chain. The anchor grabbed and dug in, but I stayed awake until the sun came up, and had the motors running for a while. Instruments told me that I was securely anchored, but I was not trusting them yet.

When daylight came, it was clear that we were anchored well, and I went to sleep. I was a nervous wreck after this whole ordeal. The wind stayed in the 20s from the south, so we spent another night in the bay. I have to admit that I replaced a 55# delta anchor that came with the boat with the 45# Manson. Why I got a smaller anchor I can not explain. Brain cramp or something. I re-installed the 55# delta for the coming evening, and it held just fine. We headed back to the marina the following day.

I don't know if I didn't set the anchor well enough to begin with, or what. I do think that the 45# was a bit small, and it certainly didn't hold in the initial wind and waves. On my last sailboat, I had an 80# Manson Supreme and loved it. I'm not blaming the anchor, it was just one of a few things that I probably did wrong. Although the incident left me a bit scarred, I do feel that we did everything right when the sh#t hit the fan. My wife was amazing, holding the boat steady in pounding waves and gale force winds, while I scurried about.

Back in the marina, I was able to swap my 45# Manson for a 55# Rocna, which was a great bit of luck. I haven't tried it yet, but it should be a bit better for my 32,000 lb boat. Thanks for reading. All comments and advice are welcomed, even negative stuff. I learned a lot that night that will help me be a better boater. And no, I did NOT use an anchor alarm, but I will from now on.

Cheers, Bill
__________________
Advertisement

__________________
"There is simply nothing more worth while than messing around in boats."
Montenido is offline   Reply With Quote
Old 02-15-2017, 11:02 AM   #2
Guru
 
City: Atlanta
Country: USA
Join Date: Jun 2012
Posts: 1,262
Interesting story. Sounds like your anchor is sized about right per Mansons chart. Like you said perhaps it wasn't dug in enough initially and unfortunately it didn't dig itself in but just skidded along.

A shame you didn't keep that giant 80lb anchor from your other boat. In any case, the Manson will make a great kedge for you.
__________________

makobuilders is offline   Reply With Quote
Old 02-15-2017, 11:21 AM   #3
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 7,869
Shallow sand close to a beach can sometimes be a very poor bottom for holding. The reason for this is that all the fines have been washed away thus the coarse grains provide too little holding resistance. Couple that iffy notion with wave action and lots of vessel windage, the 45# anchor may have been just too small.
sunchaser is offline   Reply With Quote
Old 02-15-2017, 11:38 AM   #4
Guru
 
North Baltic sea's Avatar
 
Country: Finland
Vessel Model: Nordic Tug 37
Join Date: Sep 2015
Posts: 913
whether it would be possible for the anchor chain twisted stem. see the link page 42 rocna. the test took place in this way, and did not turn and dug (rocna) although it is a good anchor. possibly also from the beginning too short chain of outdoor risen relative to strong winds. fortunately have time to react to the last seconds before a big damage.


http://www.google.fi/url?sa=t&rct=j&...m=bv.146786187
North Baltic sea is offline   Reply With Quote
Old 02-15-2017, 11:39 AM   #5
Guru
 
City: Seaford Va on Poquoson River, VA
Country: United States
Vessel Name: Old Glory
Vessel Model: 1970 Egg Harbor 37 extended salon model
Join Date: Jan 2016
Posts: 2,136
Those two anchors look very much identical to me.

Could the long slot have been why it dragged, if the boat swung?
About the Manson Supreme Anchor



Design of the edge you think might aid in a Rocna setting well and keeping is set.
sdowney717 is offline   Reply With Quote
Old 02-15-2017, 11:44 AM   #6
Veteran Member
 
City: Little River, SC
Country: USA
Vessel Name: Memory Lane
Vessel Model: Pacemaker 40 Motor Yacht
Join Date: Jan 2016
Posts: 57
Sooner or later we all have that experience. I am glad you came out of it OK.
Cliff Meima is offline   Reply With Quote
Old 02-15-2017, 11:46 AM   #7
Guru
 
Capt.Bill11's Avatar
 
City: Sarasota/Ft. Lauderdale
Country: USA
Join Date: Apr 2014
Posts: 5,436
F anchor manufacturers charts.

Personally I always recommend going at least one size larger than any chart suggests.

Put out the biggest anchor you can all the time. Just to avoid these kinds of situations. Especially if you have a powered windlass.

Plus use some kind of anchor drag alarm in a location where you can hear it clearly.

Glad you made it out OK of a scary situation.
Capt.Bill11 is offline   Reply With Quote
Old 02-15-2017, 11:49 AM   #8
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 7,869
Quote:
Originally Posted by Capt.Bill11 View Post
F anchor manufacturers charts. Personally I always recommend going at least one size larger than any chart suggests.
.
+1
sunchaser is offline   Reply With Quote
Old 02-15-2017, 11:50 AM   #9
TF Site Team
 
City: Westerly, RI
Country: USA
Vessel Name: N/A
Vessel Model: 1999 Mainship 350 Trawler
Join Date: Jan 2014
Posts: 1,668
It's interesting that the Manson sizing chart has a 40' -45' boat recommended to use a Manson Supreme 45Lb. However the Rocna sizing chart has you in a 33Kg (72LB). In your case, it's the weight of the vessel that is pushing you into the higher category. Manson is only using a length.

I would assume you would need to be in a 60lb Manson (I'd probably consider 80lb based on your story and the Rocna recommendations) or a 72lb Rocna.

I know Rocna indicates that they already oversize their anchor recommendations.
Shrew is offline   Reply With Quote
Old 02-15-2017, 12:03 PM   #10
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 15,787
From all the tests we all know the Supreme holds extremly well if not choked w weed. Any sign of that? You were in an area w lots of sun and in shallow water and the water may be relatively clear (I do'nt know). A good recipie for lots of bottom growth.

I agree w Mako that the 45# anchor is'nt too small. With a lesser performing anchor, possibly so but not the Supreme.

The Manson should'nt have cared how you layed the anchor down. With one rather remote posibility. Your chain comming down on top of the anchor could wrap itself around the anchor such that it could have been pulled sideways or backward in a tangled up mass of chain and anchor. 100' of chain out on top of an anchor only 12' down meant you could have dropped about 75' of chain on the anchor.
I take care to avoid that scenario by dropping the anchor till it is on the bottom stopping and having Chris start backing and then paying out rode at a rate approximating the moving boat over the bottom. Paying out the rode in a quite straight line and don't start taking up slack until the planned length of rode is out. This way I ideally arrange the rode on the bottom as if there was no water and I was walking around on the bottom.

You made no mention of the bottom type and very likely did'nt know. Any anchor has a bottom or several bottoms that it will not perform well on. I know of no problematic bottom type for the Supreme except thick weed or salad (as Steve on the boat Panope) likes to describe the weed in his area. From the pics it looks a bit like tumbleweeds and kelp together so "salad" is the perfect word.
One more possible problematic bottom would be mud. Chesapeke Bay-like mud that is very uncommon. If you review the Chesapke Bay mud test by Fortress Anchors you will see the only anchor that could have held your boat in a gale in that rare slimy type of mud would be a Fortress anchor. The favorite anchor at that time was the Rocna. Amazingly the Rocna was about the worst performing anchor in the test. The Supreme did'nt do very well either I will add. And one should always keep in mind that the bottom is the most important and uncontrolable part of the anchoring bag of variables.

If you did'nt set hard the wind should have done that job .. possibly even better that a skipper as then the setting takes place slowly (the best way to set an anchor)

As you can see there are quite a few waterloos you could have fallen into. So if I were you I'd review your technique ... polish your skills if I may say so. Blaming the anchor or it's size is not the most probable route to this dragging to never happen again. The excellent holding capabilities of the Supreme is very well documented. It should be capable of holding a 5,000lb load if set well on a good bottom.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 02-15-2017, 12:11 PM   #11
Senior Member
 
City: South East
Country: France
Join Date: Aug 2016
Posts: 473
Quote:
Originally Posted by Capt.Bill11 View Post
F anchor manufacturers charts.

Personally I always recommend going at least one size larger than any chart suggests.

Put out the biggest anchor you can all the time. Just to avoid these kinds of situations. Especially if you have a powered windlass.

Plus use some kind of anchor drag alarm in a location where you can hear it clearly.

Glad you made it out OK of a scary situation.
Well said. & an anchor drag alarm is absolutely necessary, so easy to use.
__________________
P.
Pilou is offline   Reply With Quote
Old 02-15-2017, 12:45 PM   #12
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 15,787
What is frequently overlooked is the standards that the size recomendations are written for. Very wide range here. Some I belive are rated for not much more than light breezes. Rocna rates for higher breezes of perhaps 40 knots. The best anchor size charts will give recomendations for several wind velocities. Some may not include enough positive bias for weight and even more wo'nt include enough. Thus there's a wide range of pits to fall into.

Whenever I read "get a size larger" l think of all the vessels that have relatively small anchors and most of them are old school w only 1/5 to 1/10th of the holding power of the newer anchors. Frequently these are commercial vessels run by professionals.

In a situation like the OP's almost always many here on TF will make big noises about getting a bigger anchor. It's easy advice that requires little thought. More often I think that evades the "problem". And if you actually do get a bigger anchor and it was a Rocna you'd have a really huge anchor. With other brands that rate for light breezes obviously getting a bigger anchor is or may be the right choice. It's always the right move to get an bigger anchor when you're anchor is too small but more often that's probably not the case.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 02-15-2017, 01:03 PM   #13
Veteran Member
 
Waywego's Avatar
 
City: Rhode River, MD
Country: USA
Vessel Name: WayWeGo
Vessel Model: Trojan F36
Join Date: Oct 2007
Posts: 57
It seems to me that scope might have been an issue in your case. Manson recommends a minimum of 10:1 scope for 35 knot winds. Not knowing the height of your bow roller, I am guessing 5', giving you a vertical height of 17'. With 100' of chain out, you had a scope of under 6:1.


If there were any issues of bottom condition or poor set, that would only make the limited scope more of an issue. I think that the greater holding power at lower scope ratios of some of the current generation of anchors tends to give us false confidence in their abilities in heavier weather.


Then again, it never hurts to have a bigger anchor.
Waywego is offline   Reply With Quote
Old 02-15-2017, 01:19 PM   #14
Guru
 
dhays's Avatar
 
City: Gig Harbor
Country: United States
Vessel Name: Kinship
Vessel Model: North Pacific 43
Join Date: May 2015
Posts: 7,954
I am very happy that the OP was able to get out of a dicey situation with only a loss of sleep. Nice job Captain!

I have a 43' boat with a relatively large amount of windage. As I look at the sizing chart , I would have gone with a 60# anchor. As Manson says;
Quote:
Finally the vessel usage should also be factored in ie whether the anchor will only be used as a "lunch pick" in fair weather for day outings or indeed whether the vessel will be going on extended coastal or offshore cruising. If in any doubt about anchor selection always use a bigger anchor, in bad weather or motoring failure, it is the only thing you can rely on to save the lives of you and your crew.
Sure more scope would have been helpful, but you had better than 5:1 which I normally would consider adequate until the wind decided to kick up a lot.

Maybe the anchor wasn't well set? It did have an opportunity to soak quite a while so again, I would have thought it would have been well set.

Maybe 3/8" instead of 5/16" chain would be better? That is just getting way too picky.

I guess I am suggesting that I could easily have found myself in that same situation. No I don't use an anchor alarm most of the time either.
__________________
Regards,

Dave
SPOT page
dhays is offline   Reply With Quote
Old 02-15-2017, 01:31 PM   #15
Guru
 
ranger42c's Avatar
 
City: Maryland
Country: USA
Vessel Model: 42' Sportfish
Join Date: Aug 2013
Posts: 4,436
Quote:
Originally Posted by Nomad Willy View Post
One more possible problematic bottom would be mud. Chesapeke Bay-like mud that is very uncommon. If you review the Chesapke Bay mud test by Fortress Anchors you will see the only anchor that could have held your boat in a gale in that rare slimy type of mud would be a Fortress anchor.

Well... from that test.

I had hoped Fortress would have been able to include the SuperMAX in those tests, but they didn't, for various reasons. Think it would have done well, though, from my experience.

-Chris
__________________
South River, Chesapeake Bay
ranger42c is offline   Reply With Quote
Old 02-15-2017, 01:40 PM   #16
Veteran Member
 
Waywego's Avatar
 
City: Rhode River, MD
Country: USA
Vessel Name: WayWeGo
Vessel Model: Trojan F36
Join Date: Oct 2007
Posts: 57
Quote:
Originally Posted by dhays View Post
I guess I am suggesting that I could easily have found myself in that same situation.
+1 on that, though I suspect we would not have done such an excellent job getting out of trouble. Most likely, we would have been on the beach or have damaged our running gear.

It says a lot about you and your wife to have kept level heads and moved so quickly after just being woken up!
Waywego is offline   Reply With Quote
Old 02-15-2017, 01:46 PM   #17
Guru
 
City: Seaford Va on Poquoson River, VA
Country: United States
Vessel Name: Old Glory
Vessel Model: 1970 Egg Harbor 37 extended salon model
Join Date: Jan 2016
Posts: 2,136
Quote:
Originally Posted by dhays View Post
I am very happy that the OP was able to get out of a dicey situation with only a loss of sleep. Nice job Captain!

I have a 43' boat with a relatively large amount of windage. As I look at the sizing chart , I would have gone with a 60# anchor. As Manson says;


Sure more scope would have been helpful, but you had better than 5:1 which I normally would consider adequate until the wind decided to kick up a lot.

Maybe the anchor wasn't well set? It did have an opportunity to soak quite a while so again, I would have thought it would have been well set.

Maybe 3/8" instead of 5/16" chain would be better? That is just getting way too picky.

I guess I am suggesting that I could easily have found myself in that same situation. No I don't use an anchor alarm most of the time either.
Just finished reading this, idea is heavier chain wont help in a heavy blow, as it will be straight line from boat to anchor, no catenary which lowers the anchor shank down to the sea bed.

http://www.petersmith.net.nz/boat-anchors/catenary.php
sdowney717 is offline   Reply With Quote
Old 02-15-2017, 02:42 PM   #18
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 12,147
Thanks for posting this, Bill. Glad to hear it all turned out OK. Sounds like you dodged a bullet with quick action by a competent crew.

I have to admit to becoming a bit lax about using an anchor alarm. Too many false alarms and I'm anchoring in relatively benign conditions, but I'm vowing to change that going forward. It's too easy for conditions to change from peaceful to terrifying.

Better to suffer a few false alarms than to have a crisis develop without warning.
FlyWright is offline   Reply With Quote
Old 02-15-2017, 02:59 PM   #19
Guru
 
ranger42c's Avatar
 
City: Maryland
Country: USA
Vessel Model: 42' Sportfish
Join Date: Aug 2013
Posts: 4,436
Quote:
Originally Posted by sdowney717 View Post
Just finished reading this, idea is heavier chain wont help in a heavy blow, as it will be straight line from boat to anchor, no catenary which lowers the anchor shank down to the sea bed.

FWIW, I think his "logic" is slightly flawed. Exacerbated by a couple graphs with the horizontal and vertical scales different... perhaps trying to subtly influence the reader visually as well.

OTOH, if he's just meaning to say "all other things being equal, heavier chain ain't gonna save your bacon" -- and trying to 'splain why that is -- OK, fair enough.

I can agree that catenary isn't an "only factor" involved. I can agree that catenary often disappears in heavy weather. OTOH, depending on wind speed, "disappearance" is often temporary. And catenary in slightly heavier chain would disappear less often. Doesn't mean heavier chain will solve everything, nor does it mean chain must always be REALLY HEAVY... but as one factor in in the whole anchoring system, there's a point where "Goldilocks" chain is a good thing.

That whole "depending on wind speed" is a moving, but critical, target... and impact of a given wind speed varies with both boat weight and boat windage. And chain weight. I think sustained winds that are heavy enough to cause catenary to PERMANENTLY disappear would vary from boat to boat and that would have to take chain weight into account.

-Chris
__________________
South River, Chesapeake Bay
ranger42c is offline   Reply With Quote
Old 02-15-2017, 02:59 PM   #20
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 15,787
717,
Smith may want you to think his anchor is a substitute for chain. Or wants you to substitute chain for more anchor weight .. his anchor of course.

I'm not an avocate of lots of chain but to say chain dos'nt help is just not realistic. Unless we're talking about a very high holding anchor w light chain.

More chain will usually help IMO. However chain is most helpful during the early stages of anchor deployment especially during setting.

Putting chain weight into anchor weight always wins re ground tackle holding power per unit of weight. Anchor weight delivers more holding power than chain weight .. per pound.
__________________

__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 04:31 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012