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27-03-2013, 03:14
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#601
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cruiser
Join Date: Feb 2011
Location: Pittwater, Sydney
Boat: Lightwave, Catamaran, 11.5m (38')
Posts: 1,000
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Re: Anchors, Bigger is Better?
I've been reading some of the other threads.
The original motivation for BIB was that for those vessels inhabiting higher latitudes they should use bigger anchors (for all the reasons stated by the proponents). Severe cyclonic storms, cyclones, typhoons and hurricanes were not a major part of the original brief as it was assumed different tactics might be used (going up creeks and tying to trees, a web of anchors etc).
The thread or the topic has drifted slightly - now a major concern is - other yachts dragging down onto you. It now seems you keep anchor watches, for other yachts (which seems to defeat part of the object). There seems little point in BIB if every time a yacht anchors upwind you have need to anchor watch, just in case - we simply move and sleep soundly. When we visit Tasmania we are lucky to see more than one other yacht in such isolated anchorages. In Strahan (its on the west coast, facing the Southern Ocean) they are 'lucky' to see 40 yachts a year (outside the every 2 year rally) and its the only town. So when you are in Labrador or Patagonia - how many other yachts are there? Moreover the mantra was - all sensible blue water yachts have bigger anchors - so what are they doing in Patagonia with anchors such that you worry about them dragging down on you?
Now we appear to have so many yachts visiting high latitude anchorages (all at the same time) that other yachts dragging is actually more of a problem than anything else. My guess is that the problem, of other yachts dragging, occurs not because the other yacht is not employing BIB but because they either have 'old style' anchors and/or they do not know how to use them - like we all were 30 years ago. Equally I suspect this happens anywhere, not only in high latitudes. It also happens when the wind is not very strong (and the 'not BIB' cabal will only have one anchor deployed anyway).
The argument of 2 rodes tangling or twisting - how many times does the wind travel through 360 degrees (and again) in a storm in Labrador, or Patagonia, or Australia?
Jonathan
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27-03-2013, 04:10
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#602
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Registered User
Join Date: Jul 2012
Location: Hobart
Boat: Alloy Peterson 40
Posts: 3,919
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Re: Anchors, Bigger is Better?
Quote:
Originally Posted by JonJo
The argument of 2 rodes tangling or twisting - how many times does the wind travel through 360 degrees (and again) in a storm in Labrador, or Patagonia, or Australia?
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It's not the main wind direction that's the problem, it's the willywaws coming down off the high cliffs spinning you round and round till your dizzy! I have had my cabin windows underwater at anchor, had a heavy hard dingy flipped a fair few times, once with my father in it!
Another time at 4am it was upside down, 5am it was right way up full of water then at breakfast it was still rightway up but now empty! just the wind.
Yet another blow the inflatable dingy nearly hit the wind generator and the spray dodger got blown off. At one point in the night an anchor line got caught on the rudder... Now I like to weight them down.
In some locations the gusts can come at you from all directions. Tassies pretty good, not too gusty, southern NZ is very bad for this.
With multiple anchors you need to be able to untangle them easily or cut them, hence my extra warps being cut to 55m lengths, just let one length out for 5m water depth, two for more than that. very easy to undo the biter end and untangle if you need to. I guess running a very loose stern anchor would make sense in some of these spots.
This is definitely when one BIB anchor and heavy chain + snubber really pays off.
Multiple anchors are better in more open locations with steady consistent winds. In places like the Marlborough sounds we often found choosing a bay that was more exposed to the wind and waves actually gave us a much quieter night.
Medium constant 30-40 knot winds and a 2 foot chop. was much better than flat calm followed by 60 knots from a random direction that you got when tucked under the hills. Shore lines and a small cove is another option for dealing with these conditions, but it can be a dangerous option at times with no escape and no reaction time if something lets go.
The thing is to have options and skills to adapt to different conditions. Jim and Ann Cate have got it just right, a moderately heavy main anchor, but the flexibility to deploy a second anchor when if is needed.
If I seem conflicted on this topic it is that I have seen lots of things work. I have been surprised by how well a tiny anchor can hold in a decent bottom. And also surprised by how poorly a monstrous anchor can hold in other conditions. I have also been horrified when my sheltered nook suddenly turns into a maelstrom due to the wind shifting 10 degrees.
Keep an open mind and a flexible approach. Have a big bag of tricks ready.
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27-03-2013, 04:27
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#603
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cruiser
Join Date: Feb 2011
Location: Pittwater, Sydney
Boat: Lightwave, Catamaran, 11.5m (38')
Posts: 1,000
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Re: Anchors, Bigger is Better?
Snowpetrel,
I was going to mention 'secure' anchorages that suffer from bullets produced through 'geography' (valleys etc). The bullets can be stronger than the average winds, because they are funnelled and can develop at 180 degrees, causing the yacht to turn through 360. These conditions seldom occur in open anchorages.
Because anchorages suffering from bullets tend to be small then the 2 bow anchors and a stern anchor (or line ashore), or 2 stern anchors and one bow anchor is the answer. The bullets might be fierce but they are transitory and having 3 rodes seems to answer. We have found the wind is strong but simply not sustained - the snatch loads are due to the yacht's momentum rather than a sustained blow. Stop the movement and you stop the snatch loads. Obviously if your mindset is one big anchor then the idea of laying 2 anchors will be an unpractised task and the idea of 3 anchors incomprehensible (and you probably do not have the anchors and rodes anyway).
We actually have a mooring spring that we use for our amidships cleat, simply bowline in the centre of the line so that we can run a line forward and aft, easy for one person to secure the yacht on a pontoon/pier. The same line is long enough, at 25m, to be used as a bridle off 2 aft winches or stern cleats for a stern anchor or line ashore.
And yes we have used it in Tasmania and in Refuge Cove, Wilsons Prom.
Jonathan
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27-03-2013, 05:13
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#604
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Registered User
Join Date: Feb 2012
Posts: 2,441
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Re: Anchors, Bigger is Better?
Did you ever anchor in Catherine Cove on d'Urville Island, SnowP?
We used to stop there en route when, (barely old enough to shave), every summer we'd take our Tasman 20 from the Sounds round to Tasman Bay or the west coast of d'Urville, or vice versa.
Cherry Tree Bay is one of the worst offenders imaginable in NW weather, for what you describe.
[ON EDIT having read JonJo's excellent post: it's one of those rare open anchorages (albeit landlocked) which is extremely bullet-prone]
Happy nights with the centreboard pulled up, tied to three trees and lying to two anchors, (friendly locals, the Hartley family, took us under their wing and would lend us a massive Admiralty pick) ... while the big keelers were lighting up the night with their searchlights - two adjacent boats would have 60 knots in mutually opposite directions, in the worst case.
Sometimes we'd stay awake just to watch the fun... (in any case it was hard to sleep for the crashing and banging of hull on hull ... )
OK I exaggerated on that last bit, but occasionally it almost got that bad.
It was a rare case where getting into shallow water was a useful way of escaping, not bergs, but keelboats!
Anyway, what I was really meaning to say was: sometimes when dropping by the same venue in bigger boats, if it got too brisk for a single anchor (to which the multiple reversals at williwaw strength are a real challenge, considering the holding), I've used another dodge instead of the more common 'very loose stern anchor' you mentioned, to save winding up the bow rodes.
(Best, IMO, to use three bow anchors when it gets that bad, then no anchor ever needs to see a load reversal, and the swinging room is minimised, so you can get closer inshore than the other big boats dare - but of course then it becomes essential to prevent circles. This technique is for when it's willing enough that the cabin ports would go underwater if the anchors held the boat side-on):
I've not seen it done by others, or heard it described, so here goes:
A (long, depending on draft) shoreline, divided well aft of the transom into a two-line bridle, one running (outside everything) to the preventer block at the starboard chainplates and the other to the port block. The tails taken back to the cockpit.
Sinking line, ideally with fluoro tags and weighted midway, so you can cast off if you see some clown heading for it.
This gives the guy on anchor watch something to do, and some string to play with: If the sternline shows signs of pinning the boat side-on to a killer gust or williwaw, he or she slacks off the bridle running to the leeward chainplate, and the boat can poke her bow up into it. If the williwaw is on the bow or stern, both can stay tightish. The tricky thing is if you spot a gust approaching from the shore when you're already side on, lying to an along-shore gust. The slack tail needs to be ground in sufficiently early to get the bum up into it, otherwise you'll run over the leeward bridle line. Luckily there are enough trees that the gusts from the shore have a bit less vigour, and if you get caught, you can ease the leeward tail if there's enough spare line, and grind it back in the next lull (there are always lulls, luckily).
If the boat's heavy, and there are no low strong points on the shoreline, the stanchion bases need to be pretty strong -- unless the person on anchor watch is paying for them, or is scared of whoever is ....
But if they're alert and onto it, the sternline never needs to see much load when the boat's side-on.
The same trick could possibly be a viable way of making a two bow-anchor set tenable in less quirky places, if you started circling unexpectedly and it got just a bit too willing for a loose stern anchor.
(In Cherry Tree Bay, the holding inshore is not flash, and of course scope is always a worry when you're pulling an anchor downhill, hence the attractions of a shorefast...)
Guessing what's next so as to play the lines proactively is not easy at night, but with decent spreader lights and short watches it's doable reactively, and it certainly beats getting the rodes completely knotted.
Of course, really big boats with a stern thruster (or twin screws or vectoring drive) can use the chequebook rather than raid the lazarette... but I don't think they'd be keen on more than two bow anchors under any circumstances, and less than three makes the bow harder to pin in place for this method to work ...
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27-03-2013, 07:26
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#605
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Anchors, Bigger is Better?
Quote:
Originally Posted by JonJo
The original motivation for BIB was that for those vessels inhabiting higher latitudes they should use bigger anchors (for all the reasons stated by the proponents).
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At least for me, and I suspect generally, that is incorrect.
I was first exposed to the BIB argument by Steve Dashew, back when both he and I were exclusively tropical cruisers (and he vastly more experienced that I). Most cruisers at that time carried two anchors on their bow. He argued that you were better off carrying one at about 1.5-2x the weight. . . . Simpler, better holding, less weight on the bow. It had nothing to do with higher latitude conditions.
He would (and does) make this same argument irrespective of the anchor type, new gen or old gen. He currently has a rocna and it is BIB.
You also seem to forget that I have used rather more anchors than just the Bruce.. . . Including Ray, Rocna, supreme, fortress, danforth, cqr....in a range of sizes.
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27-03-2013, 16:07
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#606
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Registered User
Join Date: Feb 2012
Posts: 2,441
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Re: Anchors, Bigger is Better?
I don't think there's any question that Evans' point is valid
Dashew was almost unarguably the most influential single proponent of BiB from very early on
It's a matter of record that he settled on the (old gen) Bruce, prior to switching to the Rocna when he became convinced of its merits.
AFAIK that was at the same time he retired from sailing.
(I don't pretend there's any connection !)
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27-03-2013, 16:46
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#607
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Registered User
Join Date: Sep 2009
Location: on board, Australia
Boat: 11meter Power catamaran
Posts: 3,648
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Re: Anchors, Bigger is Better?
Dashew's books first published 1989 certainly took the line BIB so presumably be was advocating BIB long before.
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27-03-2013, 17:00
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#608
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Marine Service Provider
Join Date: Dec 2006
Location: Brisbane Australia
Boat: Multihulls - cats and Tris
Posts: 4,872
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Re: Anchors, Bigger is Better?
I'm with Dashew on that, and indeed Peter Smith from Rocna. If you have an anchor and another anchor and kellets and stuff all in your "Normal" setup, then you may as well put all that weight into one anchor and one system.
I'm not with Dashew on his current choice of cruising boat, however.
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27-03-2013, 17:57
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#609
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Registered User
Join Date: Jul 2012
Location: Hobart
Boat: Alloy Peterson 40
Posts: 3,919
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Quote:
Originally Posted by Andrew Troup
Did you ever anchor in Catherine Cove on d'Urville Island, SnowP?
We used to stop there en route when, (barely old enough to shave), every summer we'd take our Tasman 20 from the Sounds round to Tasman Bay or the west coast of d'Urville, or vice versa.
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I havent got my old cruising guide or charts handy and I cant remember the name... But we stopped in most of the bays around the area. The only one I never spent any time in was a nasty looking bay up the coast from greville hbr. I remember a big party once in the big bay south of greville hbr... All so long ago now. Keen to get back there again and see if it lives up to my recollections as far as wild wind. From memory the sounds seemed alot worse than the beagle channel. But we lived aboard all year round in the sounds so got caught in a few nasty winter blows.
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27-03-2013, 22:03
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#610
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Registered User
Join Date: Feb 2012
Posts: 2,441
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Re: Anchors, Bigger is Better?
In an earlier post, I made an assertion based on faulty understanding of the rigging of large Bruce anchors for the offshore industry:
<<further up the page, he contradicts the other point from nigel1's post>>
I retract and apologise and hope nobody was misled:
I misunderstood nigel1, and I now believe the unnamed person was not contradicting his point.
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27-03-2013, 22:21
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#611
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Registered User
Join Date: Feb 2012
Posts: 2,441
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Re: Anchors, Bigger is Better?
Snowpetrel
yes, even in summer the Sounds and the general Cook Strait area were still often no cakewalk.
I was on a sailing trip to the Antipodes once with a trawler skipper. It was blowing when we arrived. He reckoned it was into three figures - mercifully not where we were. (we had a 33m mast, and a 60kg CQR ... but a BLOODY big chain. Never dragged the entire time: we ran anchor watches using the radar - very handy, pre Clinton's GPS policy change...)
To put things in perspective, he described having been forced to put into Palliser Bay in a hard NW, at the spring (I think) equinox, to heave to six miles offshore and sit it out; usually in Cook Strait it's OK in NW but the S sector is the biggie, as you know.
He said the thing he remembers most vividly, and the reason he was standing off so far, despite it meant taking greenies constantly and burning fuel like a steel mill, was an occasional musical rattle of gravel on the wheelhouse deckroof and windows from the Orongorongo Ranges.
I don't have chapter and verse evidence, but it has seemed to me for the last decade or more that Cook Strait weather has been moderating steadily and is now considerably less severe.
Not to say it can't still cut up.
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27-03-2013, 23:48
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#612
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Registered User
Join Date: Jul 2012
Location: Hobart
Boat: Alloy Peterson 40
Posts: 3,919
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The worst weather I have seen anywhere in the world was off cape palliser. Got the sh*t kicked out if us on one trip south from napier. Wellington airport had 84knots and two houses in wellington lost their roofs plus a phonebox blew away... Our windspeed was locked at 60kn for about 6 hours.
Kind of glad I went through that when I was 15, now everytime I am out in something nasty I can think well at least it's not as bad as palliser.
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28-03-2013, 00:19
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#613
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Registered User
Join Date: Oct 2012
Location: Canada
Boat: Sinek, Pilothouse, 43ft
Posts: 105
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Re: Anchors, Bigger is Better?
60 lb CQR with 400' 3/8 chain for a 43' boot holds us well. We just use tons of scope.
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29-03-2013, 23:56
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#614
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cruiser
Join Date: Feb 2011
Location: Pittwater, Sydney
Boat: Lightwave, Catamaran, 11.5m (38')
Posts: 1,000
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Re: Anchors, Bigger is Better?
Rather than get all huffy, as some seem, I wondered if possibly the debate is from 2 extremes, people with smaller lightweight yachts and people with larger heavier displacement yachts and neither were considering the other's problems. Many through economic reality if they wish to cut ties with 'home' will need do so in common or garden, sometimes, small and lightweight average white production yacht and though following BIB it does not solve all the issues. So to be constructive I wonder what the advise might be.
The scenario is relevant, many from the UK take their, AWB, yachts and base them in the Mediterranean, where Noelex assures us bullets are common. So what do they do?
I follow advise and go BIB. I enter a tight anchorage to shelter, forecast to be strong (Storm) SW then veer to S, to find the anchorage leaves little room. Once the storm blows through, 3 days the winds will ease and go SE and then NE. Its sufficiently sheltered there are no seas. Most are on shortened scope. We follow suit, have little choice, cannot go anywhere else. But holding is good and we are BIB - so we are not going anywhere (ie we are not going to drag).
Sadly the anchorage is prone to winds that gust strongly from one side and then the other. We being in a lightweight, high windage vessel (cat) (but it could easily be applied to the many production yachts on the market) are veering from side to side and back and forward. The impacts are taken by the snubbers, so no snatch loads - but disconcerting none the less. But the shortness of scope does mean it is bar tight frequently. I think this is real, its actually what happens.
How do we minimise the veering, which will reduce the swift deceleration produced by the snubbers. An answer might be live with it, remember the whole idea is to have a relaxed night's sleep - but surely there is something better?
Many on their first cruise will not have long snubbers, maybe have a 2m snubber and all chain. So what's the advise.
We could anchor further out (more room) but we do have a finite amount of chain and waves are an issue, its deeper and we would still enjoy the wind gusting from side to side and more of it as less sheltered.
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30-03-2013, 00:57
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#615
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Moderator
Join Date: Jul 2007
Boat: Bestevaer.
Posts: 15,168
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Re: Anchors, Bigger is Better?
Quote:
Originally Posted by JonJo
The scenario is relevant, many from the UK take their, AWB, yachts and base them in the Mediterranean, where Noelex assures us bullets are common. .
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The Mediterranean is a big area so its hard to generalise but good "bullet's" are not common in anchorages.
My comments about strong bullets probably referred to sailing other parts of world rather than where I am the moment (although in strong wind there are always be some veering so your example is still valid)
Here in the Med the winds tend to be begin in summer (apart from certain areas), but can be more challenging in the winter. Many / most cruisers retire to marinas for winter arguing that anchoring this time of year is unsafe.
Quote:
Originally Posted by JonJo
But holding is good and we are BIB - so we are not going anywhere (ie we are not going to drag).
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In storm force winds a high percentage of boats drag. Better gear and skills help tremendously, but there are no guarantees.
Dont believe the marketing hype from the anchor manufacturers.
Quote:
Originally Posted by JonJo
How do we minimise the veering, which will reduce the swift deceleration produced by the snubbers. An answer might be live with it, remember the whole idea is to have a relaxed night's sleep - but surely there is something better?
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No one is getting a good nights sleep when anchored in storm force winds.
Long snubbers with a good deal of elasticity are vital in these sort of conditions, this would be my first consideration.
There are all sorts of methods to minimise veering.
Setting a riding sail
Dropping a second anchor (or weight) on a short scope
Tying a drag device ( such as a stout bucket ) near the ends of the boat ( bow seems most effective)
Rigging a bridle system ( even on the limited width of a monohull)
Tying a line from near the stern to the chain. Shortening the length of this will skew the boat to one side, increasing the windage, but making it more constant.
Removing furling sails. (Or other windage at the front)
Modifying the boat to increase windage at the rear (say a solar panel arch)
Anchoring from the stern (not recommended due to the increased windage)
Deploying a Kellet
All these techniques ( with the possible exception of the last) work to a certain extent, but I have found them to be more trouble than they worth.
I have no problem with someone who wants to try a second anchor for this purpose, especially on a very short scope, where many of drawbacks of second anchor are minimised.
My concern is people that have inadequate holding in their main anchor and use a second anchor, routinely, to increase their holding. I don't believe this is a good philosophy for a cruising boat.
KISS would be my advice.
If you do want to use any of these techniques practice them first in more moderate conditions. Things can go very wrong in strong wind and people get themselves injured.
Also consider what you will do with any of these devices if you do drag.
For example have a second anchor buoyed so it can be released and recovered, but consider how you will prevent this wrapping around the prop. In storm force winds there is likely to be no communication possible between the bow and helm and very limited visibility. So have a well rehearsed plan of action that considers these basic problems.
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