Anchor holding in grassy bottom

[geem]

We have been anchored at Culatra on the Algarve for a couple of weeks. We are at the Eastern anchorage. We were last here 7 years ago. The seabed has changed since we were last here. The Eastern anchorage used to be the better holding but now the seabed is thick grass.
Whilst we have been here we have had pretty benign conditions. Winds have rarely got over 20kts. Nobody has dragged until winds hit the magic 20kt button.
So, who has been dragging? Well only two anchor types have dragged. The most common dragger is Delta. Several boats with Delta anchors have dragged. A British boat with a CQR has dragged a few times. No other anchor type has dragged.
Not an exhaust survey but Delta anchors and seagrass don't seem to work. We do get a tidal current here so anchors are having to deal with a 180 Deg reversal. Clearly this combination doesn't work for Delta anchors.
A local Portuguese sailer we Met who also has a Delta says he needs 50m of chain out in 6m of water otherwise it will drag here

 

[capnsensible]

Ive anchored there a few times. CQR on my school yacht. Always comes up thick with weed, I always used to put out loadsa chain. ?

 

[LittleSister]

Meaningless unless we also know how prevalent the Delta anchors are in the boats present.

 

[Graham376]

Seems the policia must have stopped kicking people out of that anchorage, it's one of two in which anchoring was/is banned to protect sea horses, they want the grass to spread.

 

[geem]

Meaningless unless we also know how prevalent the Delta anchors are in the boats present.

Well we don't have one? guys next to us have a Rocna. It wasn't supposed to be scientific. We are anchored with 30m of chain. If boats all around are dragging on Delta anchors with similar lengths of chain deployed than something is wrong. We have counted 7 boats with dragging Delta anchors and two collisions. It's not even been windy

 

[noelex]

The Delta and most other fixed convex plough anchors are not generally good in weed. The thick bulky toe, combined with the low toe weight does not help with penetration through weed roots.

If anyone is looking for a recommendation of an excellent general purpose anchor that works well in weed then my Mantus M1 has been performing fantastically well in this substrate.

[IMG]

https://imgur.com/q8AbIId

[/IMG]

This photo shows the thin tapered tip profile, very different to the convex plough models:

 

[geem]

The Delta and most other fixed convex plough anchors are not generally good in weed. The thick bulky toe, combined with the low toe weight does not help with penetration through weed roots.

If anyone is looking for a recommendation of an excellent general purpose anchor that works well in weed then my Mantus M1 has been performing fantastically well in this substrate.

[IMG]

https://imgur.com/q8AbIId

[/IMG]

This photo shows the thin tapered tip profile, very different to the convex plough models:

That grass is what we are anchored in. A Spade anchor is doing it for us. We couldn't be happier with its performance. We have only anchored since we left Caernarfon on 6th July.

 

[Neeves]

The Delta and most other fixed convex plough anchors are not generally good in weed. The thick bulky toe, combined with the low toe weight does not help with penetration through weed roots.

If anyone is looking for a recommendation of an excellent general purpose anchor that works well in weed then my Mantus M1 has been performing fantastically well in this substrate.

[IMG]

https://imgur.com/q8AbIId

[/IMG]

This photo shows the thin tapered tip profile, very different to the convex plough models:

Not everyone is using a 50kg anchor - I think Peter Smith would suggest a 33kg Rocna for your size of yacht (which I agree may not be very good in weed, due to the clogging issue between fluke and roll bar.

Just out of interest Noelex - you are keen to damn other anchors - have you ever used an Anchor Right Excel, or Spade over a cross section of seabeds? I only ask as your negative comments, and praise for the M1, are in complete contradiction to the work conducted under the Panope banner - where the Excel comes at the top of the heap. In fact if you drop out the subjective comments (how do you judge galvanising by looking) and price (over 100 nights at anchor, say, price is really totally insignificant) then Excel, Spade and Viking are streets ahead of the M1. In fact looking at the Panope spread sheet - you seem to have a lemon.

Jonathan

 

[prv]

That grass is what we are anchored in. A Spade anchor is doing it for us. We couldn't be happier with its performance. We have only anchored since we left Caernarfon on 6th July.

I'd have confidence in my Spade there too. I believe it was originally developed specifically for grassy bottoms?

Pete

 

[Neeves]

It depends on the weed, there is weed and weed.

These are both Deltas, or delta variants/clones

But one problem is that as the anchor works its way through the weed then the weed clogs between fluke and shank - this will happen with any anchor. With a clot of weed (with or without roots) the anchor will struggle to penetrate - if at all. To suggest that an anchor has some special characteristics to mitigate the clogging by weed - is marketing at its most dishonest.

The second problem is that with the anchors most of us use 10 - 30kg the anchor, part due to the above, will not penetrate very deeply and the hold is contingent on the strength of the weed root system (which is commonly not strong).

The best anchors are those like a Spade or a Excel whose weighted toes will allow them to penetrate a bit more easily. Roll bar anchors - especially smallish one, under 30kg - will clog as the weed, roots and mud are compressed under the roll bar.

If there are sand, or weed free patches - find them and drop the anchor in the weed free area (commonly identified as being pale patches, the weed is usually black). Better move to somewhere without weed

Delta, CQR and Mantus (which sets very shallow), are not renowned as 'diving' anchors at the best of times.

For the shallow set of a Mantus anchor see

An Inquiry into Anchor Angles - Practical Sailor

Adding more chain to an anchor will do little to increase hold - its a placebo. In shallow water there is no catenary of note - you simply have an anchor attached to an inextensible length of steel. Having a decent snubber will reduce any snatches - which might help.

And Geem - you might not have had a statistically acceptable survey - actually considering the numbers you quote - really useful and significantly better than not reporting. Keep up the reports - and if you are heading west you will not be doing much anchoring for some time........ Fair Winds.



Take care, stay safe

Jonathan

 

[Neeves]

I'd have confidence in my Spade there too. I believe it was originally developed specifically for grassy bottoms?

Pete

Yes - you and Geem (and ourselves) have actually used a Spade - so your comments have some substance.

Jonathan

 

[geem]

View attachment 123155

View attachment 123156


It depends on the weed, there is weed and weed.

These are both Deltas, or delta variants/clones

But one problem is that as the anchor works its way through the weed then the weed clogs between fluke and shank - this will happen with any anchor. With a clot of weed (with or without roots) the anchor will struggle to penetrate - if at all. To suggest that an anchor has some special characteristics to mitigate the clogging by weed - is marketing at its most dishonest.

The second problem is that with the anchors most of us use 10 - 30kg the anchor, part due to the above, will not penetrate very deeply and the hold is contingent on the strength of the weed root system (which is commonly not strong).

The best anchors are those like a Spade or a Excel whose weighted toes will allow them to penetrate a bit more easily. Roll bar anchors - especially smallish one, under 30kg - will clog as the weed, roots and mud are compressed under the roll bar.

If there are sand, or weed free patches - find them and drop the anchor in the weed free area (commonly identified as being pale patches, the weed is usually black). Better move to somewhere without weed

Delta, CQR and Mantus (which sets very shallow), are not renowned as 'diving' anchors at the best of times.

For the shallow set of a Mantus anchor see

An Inquiry into Anchor Angles - Practical Sailor

Adding more chain to an anchor will do little to increase hold - its a placebo. In shallow water there is no catenary of note - you simply have an anchor attached to an inextensible length of steel. Having a decent snubber will reduce any snatches - which might help.

And Geem - you might not have had a statistically acceptable survey - actually considering the numbers you quote - really useful and significantly better than not reporting. Keep up the reports - and if you are heading west you will not be doing much anchoring for some time........ Fair Winds.



Take care, stay safe

Jonathan

I confirm that all Delta anchors were on boats that we're likely to be using Delta anchors less than 30kg. There are no sandy patches unless you anchor in the very shallow tidal water that isn't deep enough. I have paddleboarded all over the anchorage and I haven't seen any sandy patches.
I got friendly with a local Portuguese sailor here. I asked him why he used a Delta if he knew they were so bad in the grass here. He said Spade anchors were too expensive. He has now left to sail up to Lisbon to get his teak decks replaced. €20,000 apparently. Work that one out. Lots of money for decks but hasn't got a few hundred quid for an effective anchor

 

[NormanS]

IF I was anchoring in grass, I would use my Fisherman anchor. (Ready for incoming).

 

[Neeves]

I was going to elaborate on this quote:

'The Delta and most other fixed convex plough anchors are not generally good in weed. The thick bulky toe, combined with the low toe weight does not help with penetration through weed roots.'

But it seems that this would not accord with the mood of some members. I'll leave it for a few days, weeks, years - I do it voluntarily and if the mood is against it - I'll keep my fingers off this keyboard.


Maybe some might value checking this thread:

Photos of Anchors Setting - Cruisers & Sailing Forums

and wonder why the observations in this article, link below, were never mentioned:

Photos of Anchors Setting - Cruisers & Sailing Forums

There is a contradiction and a danger


And for those who suggest that I consider myself an expert - on things - anchoring. I am insufficiently arrogant and certainly not that stupid to ever claim to be an expert - its far too complex a topic for the likes of me. I just feel it reasonable to share my experience - I have said it previously - if you don't like what I post, if you are not interested in anchoring - don't read my posts. If you do read my experiences and dislike what I say and have background to offer another point of view - tell me - I am very happy to consider other views and contrary views - the topic, anchoring, is far to complex no-one can ever know it all.

We now know subliminal marketing is not an issue - I look forward to people taking advantage.

Take care, stay safe,

Jonathan

 

[geem]

IF I was anchoring in grass, I would use my Fisherman anchor. (Ready for incoming).

An American pal of mine had a 38ft boat. His main anchor was a 75lb bronze fisherman's anchor. It was huge. He would always set two anchors in non tidal waters

 

[NormanS]

An American pal of mine had a 38ft boat. His main anchor was a 75lb bronze fisherman's anchor. It was huge. He would always set two anchors in non tidal waters

In my quiver of anchors, there is a 20kg self made fabricated fisherman with slightly larger palms than normal. To be honest, the fisherman hasn't been used for some years, but it's there, just in case. I find that the use of a Fishfinder to select a good clear site, is probably more important than having the latest fashionable anchor. Moving windage further aft to reduce yawing can also make a big improvement in successful anchoring.

 

[geem]

In my quiver of anchors, there is a 20kg self made fabricated fisherman with slightly larger palms than normal. To be honest, the fisherman hasn't been used for some years, but it's there, just in case. I find that the use of a Fishfinder to select a good clear site, is probably more important than having the latest fashionable anchor. Moving windage further aft to reduce yawing can also make a big improvement in successful anchoring.

We tend to not bother too much about whether we anchor in grass or not. We know the anchor works. We do set with gradually increasing revs when anchored in grass. It probably the only seabed where I use full revs. Having had unfashionable anchors in the past with less than perfect holding characteristics, I would not revert back

 

[Blueboatman]

In my time I used to sail into and out of the lagoon on Culstra and park on the beach .
Happy days . Nip over to Olhao under sail for the supermarket and Fado, market and fish , sail back again on one tide ?
I gather that the lagoon has been wired off for years now, people abiding it with cluttered mab flotilla
Was a fab place but a bit bouncy on the sand on a NE at hw springs

 

[NormanS]

We tend to not bother too much about whether we anchor in grass or not. We know the anchor works. We do set with gradually increasing revs when anchored in grass. It probably the only seabed where I use full revs. Having had unfashionable anchors in the past with less than perfect holding characteristics, I would not revert back

Oh dear! Cruelty to seahorses. ?

 

[geem]

Oh dear! Cruelty to seahorses. ?

At least we don't plough up their home?