Mantus swivel affects anchoring with Manson Supreme

[bbalan]

Hi All,
We have recently identified an anchoring problem that has been bothering us for over a year. A bit of background first:


We purchased a 27kg Manson Supreme in New Zealand in 2009. Our 25kg Delta had been doing a great job for many years. However, after a 30+ knot squall came through when anchored in Tahiti in 2008, I dived down to view the tracks in the sand left by our Delta and a neighboring (and similarly-sized) boat's Manson. The Manson had reset much faster – I was sold.


We've been extremely happy with our Manson and have spent years (literally) at anchor hanging on it.


We used a WASI Powerball until 2019. The Powerball was by then 20 years old and I thought it prudent to replace it. We purchased and installed a Mantus Anchor Swivel S2. During the last year, we have had occasional difficulties setting our anchor in places that should have been easy given the depth and bottom. Last July, at Isla Monserrat in the Sea of Cortez (Mexico), we were having so much trouble that I ended up diving down to watch the anchor while my wife drove the boat. I found the anchor was lying on its side and dragging. I stood it upright and then it set.


This year, with our plans to return to French Polynesia thwarted by the pandemic, we ended up staying in Mexico again and have since visited many of the same places we anchored last year. In several of these spots, we had problems getting our Manson to set.


One of the problems with the Mantus swivel is that it does not fit well on the lower (normal) hole of the Manson’s shank. Thus we were forced to put it in the upper slot. We would rather not have done this as we feel the slot is a bit gimmicky and prefer the regular hole in the shank. Thinking that perhaps the anchor set problems were caused by using the upper slot, we replaced the Mantus swivel with a regular shackle and connected the chain to the lower hole.


This change corresponded with us revisiting 5 anchorages that we had just visited the week before – some of which we experienced anchor set problems in --- including the anchorage on Isla Monserrat where we had problems in 2019 & 2020.


I cannot tell you how happy we were to discover that the anchor set the first time at every single anchorage. Suddenly we had our old anchor back! During our 60,000+ miles of cruising, we have anchored so many times in so many conditions that we can often tell pretty quickly when we get a good set – even before we back down. It was clear that the way the anchor behaved changed when we removed the Mantus swivel.


Apologies for the long story but I want to back this up with our experience. In short, I would NOT recommend using a Mantus swivel with a Manson Supreme.


In 2016, Practical Sailor wrote about the Mantus swivel “This swivel’s weight could impact anchor balance as it sets…”



They were absolutely correct in their concerns.


I am sailing in the Sea of Cortez right now and only have occasional internet – so apologies for long delays if there are any questions.


Cheers,
Bruce
s/v Migration
Isla Coronados, BCS, Mexico


Migrations
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[ranger58sb]

Why did you want a swivel in the system in the first place? Starting with the WASI and the Delta, then the Mantus and the Manson? What problem was it meant to solve for you?

-Chris

[Dockhead]

Originally Posted by ranger42c

Why did you want a swivel in the system in the first place? Starting with the WASI and the Delta, then the Mantus and the Manson? What problem was it meant to solve for you?

-Chris

Same question here. If it's working well for you without a swivel then what's the problem? And why were you using the swivel in the first place?

I needed a swivel when I was using a 121 pound Rocna, because that anchor was balanced to come up upside down. I needed the swivel so that I could horse it around with a boathook in order to get it into the bow roller.

With better balanced anchors I don't need any swivel. Not using a swivel is lighter, stronger, cheaper -- all good. Not just the weight of a swivel -- particularly a massive one like the Mantus -- but also the VOLUME has got to be an issue, at least a minor one, getting into the seabed for a deep bury, getting into the bow roller, etc.

[Chotu]

First, forget the swivel.

Second, don’t use the upper track slot in the Manson for your primary attachment! It’s to put an anchor trip line on to free your anchor it it becomes tangled or hooked on an object below.

Only use the small hole to attach your boat. Not the upper track slot.

Use the upper track slot with a small line tied to a float ONLY. Then if you are snagged, you can pull the small line in different directions to free the anchor.

You’re lucky you haven’t lost your boat.

[wholybee]

Many swivels will bend or break if sideloaded. If you decide you need one, connect it to the anchor with a few links of chain. Then you can use to correct hole, and also not side load the swivel.

[thinwater]

Another problem with the upper slot on the Manson is that it changes the anchor geometry. Obviously, it changes the whole shank angle.



I think most sailors think they should get rid of the upper slot.

[Izikalvo]

Maybe it is the slot and not the swivel? You can put a stopper on the slot if you really want to use the swivel which i don't think you should.

[Ranger2727]

I have a Mantus swivel, the smallest they build, was recommended by the chain manufacturer after I complained about the wear on the rope/chain gypsy. I wore out three gypsies on my Lewmar winch. Their explanation was that as the boat sails at anchor, the chain rolls on the bottom and twists. This twist is carried up the chain to the gypsy, as the chain has a slight twist, the twist rotates ever so slightly that it wears the softer bronze, enlarging the slots for the chain and eventually causing the chain to slip in the gypsy. I too have a Manson Supreme 35lb on my RangerTug 27; I do sleep soundly at night with all that weight
I have a bronze roller that is slotted for the chain, so no twist is carried to the gypsy, but as the chain is retrieved the twist is relieved in the swivel, since the anchor may still be on the bottom. This has been very satisfactory for my cruising style and have not replaced the gypse in four years (previously it was every year!)

[Nicholson58]

Originally Posted by Dockhead

Same question here. If it's working well for you without a swivel then what's the problem? And why were you using the swivel in the first place?

I needed a swivel when I was using a 121 pound Rocna, because that anchor was balanced to come up upside down. I needed the swivel so that I could horse it around with a boathook in order to get it into the bow roller.

With better balanced anchors I don't need any swivel. Not using a swivel is lighter, stronger, cheaper -- all good. Not just the weight of a swivel -- particularly a massive one like the Mantus -- but also the VOLUME has got to be an issue, at least a minor one, getting into the seabed for a deep bury, getting into the bow roller, etc.

Same on Roxy, 121# Rocna. We added an anchor forerunner. The swivel bit is a few links from the shank attachment and the parts pass easily over our 10 inch bow roller. Forerunner shown was $168, hot dipped galvanized high strength. This arrangement sets reliably in any suitable bottom.

[Group9]

Originally Posted by thinwater

Another problem with the upper slot on the Manson is that it changes the anchor geometry. Obviously, it changes the whole shank angle.



I think most sailors think they should get rid of the upper slot.

I’ve owned two Manson Supremes and never used that slot.

[ski69sail]

.

Thanks for a great and informative post.

Ray

..

[bbalan]

Originally Posted by Chotu

Second, don’t use the upper track slot in the Manson for your primary attachment! It’s to put an anchor trip line on to free your anchor it it becomes tangled or hooked on an object below.

Only use the small hole to attach your boat. Not the upper track slot.

Use the upper track slot with a small line tied to a float ONLY. Then if you are snagged, you can pull the small line in different directions to free the anchor.

Hi Chotu,
Actually the upper slot is for the chain. It's one of the 'features' of the Manson Supreme. Made for when you might get your anchor caught in rock. Check it out on their website. But I don't think it's a great feature.
Bruce

[bbalan]

Originally Posted by ski69sail

.

Thanks for a great and informative post.

Ray

..

Thanks for saying so, Ray. Much appreciated.

Fair winds,
Bruce

[bbalan]

Originally Posted by Izikalvo

Maybe it is the slot and not the swivel? You can put a stopper on the slot if you really want to use the swivel which i don't think you should.

Izikalvo,
I believe you are partially correct. I think the anchor sets worse in sand with the upper slot but not as bad as it was setting with the Mantus swivel -- at least based on prior experience with the WASI and the upper slot.


Cheers,
Bruce

[bbalan]

Hi All,
Thanks for the replies. Many have asked why I have a swivel in the first place. I don't want to get into a swivel debate --there have been plenty on CF already!


For us, we find it VERY useful when the anchor comes up facing the wrong way. It is much easier to reach over the bow pulpit and spin the anchor with a swivel than to try to spin anchor and flip the chain in the slot on the roller. Especially if it happens in nasty weather. It is also useful when we are at anchor for weeks in the same spot with changing winds and/or currents. The WASI is stronger than shackles that fit our 3/8" HT chain. I'm sure many will disagree because of the side-loading argument. However, it's worked well for us for 20+ years and 60,000+ NM and in many different anchoring conditions.
Heading off internet for the next 2 months. Fair winds!
Cheers,
Bruce
s/v Migration
Santa Rosalia, BCS, Mexico
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