Category: Articles

A look at anchors and anchor rodes

Two anchors and cables should be carried on board but what size and types of anchor and what lengths and diameters of chain and warp? If you have a lot of time at your disposal you could research the following:

• Test carried out on the USA early 1990’s collated by Robert Smith and published ISBN 0-9651350-0-4
• Tests in 2003 and 2009 by French magazine Voiles et Voilers and published in November 2009 edition of UK’s Yachting Monthly
• Tests carried out in recent years in Scotland by cruising yachtsman John Knox with articles published in Practical Boat Owner magazine. Contact John at Knoxjohnh@aol.com
• MGN 280 Table 20.1 available via MCA website. This specifies minimum requirements for small commercial vessels.
• Test results by individual manufacturers of anchors. Caveat emptor!

The above list is by no means exhaustive but I suspect that 95% of cruising yachtsmen have neither the time nor the inclination to fully research the complex issues of anchor design, catenary and scope. My job as a sailing instructor is to attempt to simplify things so that those on the learning curve can “just do it!” This may be mission impossible when it comes to anchoring but I will give it a try over the next 3 articles.

It’s easy to say the “more the merrier” or the “bigger the better” when it comes to choice of hardware but only a few yachts are large and heavy enough to follow these maxims. Most of us have to make careful choices based on available space, weight and practicalities of handling our ground tackle. Most cruising yachtsmen are very safety conscious and I hope the following comments will reassure you that what you have on board already is perfectly adequate.

The Anchor

In the last 10-15 years a considerable number of new anchors have appeared on the market and independent tests indicate that they should be taken seriously. (Not all tests carried out have been equally rigorous or comprehensive.) The bottom line is that you can achieve greater holding power relative to size and weight than some of the older generation of anchors which have been on the market for a long time. This does not mean that you should rush to change the old faithfulls which have served us well for many years. If you are thinking of extending your cruising grounds and spending more time at anchor you might want to take a look at some newer models. I am not going to identify which anchors I currently use as I don’t want the good to become an enemy of the better but I can offer some comments about size.

Westbound Adventurer is a 10 metre Sigma 33C probably on the smaller side of average if there is such a thing as an average size cruising yacht. Displacement when fully loaded is probably about 5 tons. I have a 15 kg. “storm” anchor which is used in good holding in winds of F7 or more. I would use it in winds lesser than F7 if I had any doubts about the quality of the holding on the seabed. I also have a 10 kg “working” anchor which is used most of the time. Ease of handling is important as far as RYA Training is concerned especially as Westbound Adventurer spends 80 – 120 nights at anchor each year plus many lunchtime stops at anchor. I also have a third light anchor and cable for certain training purposes but there is no need for most cruising yachts to have a third system. I believe that 15 kg is as heavy as most people can haul up manually given that there will always be the extra weight of chain relative to the depth. Beyond 15 kg an anchor windlass becomes highly desirable if not essential. Some will regard it as highly desirable on all occasions irrespective of weight. If we can have furling sails and lazy jacks to make life easier why not an anchor windlass? There is no windlass on Westbound Adventurer but I will not hesitate to get one fitted when I retire from RYA Training.

The 10 and 15kg anchors are kept in the anchor well along with the main cable. This allows the anchors to be changed on the foredeck if required. I keep the second anchor cable and the third system in a locker amidships as it is not desirable to have too much weight up forward even if there is space.

 

The Anchor Cable or Rode

The issues of Catenary and Scope are distinct but not separate.

There are many experienced yachtsmen who prefer to have all chain cable and lie at anchor with a few metres under their keel. This allows the weight of chain to form a curve or catenary. When the wind increases this catenary is the first defence in the system and can act as a stabiliser to the motion of the boat at anchor. In this context it is possible to be securely anchored with a scope of only 1 to 3. I believe however that this will only be the case in light to moderate winds.

When it blows hard enough for the cable to be fully stretched the catenary has no further purpose. It has disappeared. The security of the system is now dependent on minimising the angle between the seabed and the chain closest to the anchor. This is achieved by increasing the scope. If in doubt let it out! When it blows up your cable does nothing for you in your anchor locker.

For those with an all chain cable, a length of nylon needs to be added to the system when it blows really hard. Even in light to moderate winds many yachtsmen will add a rubber snubber or a short length of nylon warp over the bow roller to eliminate the nocturnal grunting of chain on the bow roller. The occupants of the forward cabin will appreciate this.

In very strong winds when an all chain cable becomes fully stretched great shock loads are put on the weakest links in the system. Attach nylon warp to the chain outboard of the bow roller and secure the inboard end of the warp to a strong point on the foredeck or take the warp to a primary winch in the cockpit. Nylon is very strong and it stretches which is just what is needed to absorb the shock loads created by a boat surging at anchor in a strong gust. The longer the length of nylon the more energy can be absorbed. It is prudent to insert chaffing protection for the nylon warp.

It is theoretically possible for security at anchor to be achieved by catenary alone but the amount of chain required would make this totally impractical for most yachts.

How hard does it have to blow for an anchor cable to be fully stretched? The variables involved are:

• the strength of the wind
• the windage factor of the boat both head on and after it tacks through the wind at anchor
• the sea state within the anchorage
• the weight of chain deployed.

 

The amount of chain to be kept on board should be considered in terms of its weight as well as its length. Weight is determined by the diameter of each link. I would suggest that the maximum diameter of chain that is practical to handle manually is 3/8” or 10mm. If you have a windlass this will determine the diameter of chain used. On some models it is possible to change the pall to suit the chain diameter. The length of chain for your anchor cable depends on the sort of depth you want to anchor in, the size of your boat and its arrangements for stowage. Many cruising yachtsmen will carry 40-60 metres of chain on their main cable but considerably less on their second cable. 40 metres of chain allows a scope of 1 to 4 in 10metres of water or a scope of 1 to 8 in 5 metres of water. Some will argue that the more chain you can carry the better, but is this always the case?

My own solution to the balancing act of security at anchor versus weight and sailing performance is different to the practice of many cruising yachtsmen who would typically have a larger yacht with fewer crew and more space for heavy ground tackle.

With a draft of 1.3m I anchor in shallow water (5 – 7 metres at the top of the tide) with a cable of 20 metres of 10mm chain spliced into 20 metres of nylon warp. (20 metres of 10mm chain is the same weight as 32 metres of 8mm chain often used on yachts of this size) For an overnight anchorage I have all the chain in the water and create a minimum scope of 1 to 4 by letting warp out if in 6 or 7 metres depth. My second cable is identical to the first but chain and warp are shackled together rather than spliced. This allows the chain of the second cable to be added to the first cable on the very few occasions I anchor in deeper water. RYA Day Skipper Course Notes recommend a minimum scope of 1 to 4 for an all chain cable and this is excellent advice while at anchor in light to moderate winds. As the wind increases we need to increase the scope by letting out more cable but this does not have to be more chain.

A fully stretched cable runs more or less straight from the anchor to the bow roller so the geometry is the same if the anchor cable is all chain, half chain and half nylon or all nylon. It is not desirable to have an all nylon anchor cable because of the risk of chaffing on the seabed and the motion of a yacht at anchor with an all nylon cable. It would also be difficult to set an anchor with an all nylon cable. It may be desirable to have an all chain cable (to which nylon warp is added in very strong winds) but it is not practical to do so on many yachts due to space, weight and sailing performance.

The bitter end of the anchor cable should be arranged so that it can be brought onto the foredeck still secured below. This allows the system to be buoyed and dumped in a hurry if required. How long would it take to haul up the anchor if you had an MOB at night drifting downwind from your anchored boat?

To fully explore the delights of the Scottish Hebrides we need the confidence to anchor in gale force winds. The good news is that summer gales are usually well forecast and short lived. Your first experience of gale force winds at anchor will cause you some anxiety. It is only by doing it for real that you loose your natural anxiety and gain confidence in your ground tackle. Read “Digging in for a Blow”

RYA Teaching Establishments are highly regulated. Sail Cruising Schools are subject to 3 separate pre-arranged inspections and 2 possible unannounced inspections by the RYA or MCA. Of the 3 pre-arranged inspections the annual inspection of the yacht has a check list which currently runs to 164 items.

One area in which there is surprisingly very little regulation is the choice of headsail system for a cruising yacht. It is up to each RYA Cruising School to choose between a furling, luff groove or hank on headsail system.

For my own single yacht sailing school I have attempted to combine all 3 systems with a 5 piece headsail wardrope (excluding the spinnaker).

In this article I describe the 2 headsails used during every RYA Course and in next month’s article I drag the remaining 3 headsails from their locker.

WESTBOUND ADVENTURER is a masthead rig Sigma 33C which is the cruising version of the popular Sigma 33 OOD racing fleet. The headsail system which I had fitted is a twin luff groove Rotostay furling system with a slot in the drum to accommodate a non furling headsail.

NO.1 HEADSAIL is a full luff length 150% genoa which is used when winds are light. The tack of this sail is attached to a U-bolt on the deck about 12″ below the furling drum. The top of the luff is fed into one of the twin grooves and the halyard attached directly on to the head of the sail. Once the sheets have been secured on the clew the sail is almost ready to hoist. The only problem to be resolved is what to do with the swivel which is an essential part of any furling system but redundant for this genoa. It could be hoisted to the top of the forestay via a burgee halyard or it could be allowed to rest on the top of the luff and ride aloft with the sail.

I used the latter method for a while but found that it started to damage the top end of the luff so I now attach the swivel to the head of the sail via a short chord so that it rides aloft about 2″ above the luff.

When this headsail is fully hoisted the bottom end of the luff is fed through the slot in the furling drum.

Using this sail in light airs creates several valuable learning experiences which the use of a single furling headsail throughout a 5 day RYA Course does not allow:

• Hands on experience of preparing, setting and handing a non furling headsail.
• Hands on experience of stowing on side deck/guard rail ready for rehoisting.
• Hands on experience of practical solutions when anchoring with a non furling headsail.
• Hands on experience of skirting the foot of a large headsail when tacking to windward.
• Hands on experience of folding and bagging a headsail on deck while underway.

No.3 HEADSAIL is the yacht’s working headsail and I offer no apology for the fact that this is a furling headsail. I guess that 90% of cruising yachts have furling headsails and as the RYA Cruising Syllabus is designed for cruising yachtsmen it is entirely logical that sailing school yachts should have this system. This particular furling headsail was designed to meet a variety of needs:

• I wanted it to take over where my No.1 genoa leaves off so that with a few rolls in the headsail it is almost as efficient as a dedicated storm jib.
• I wanted a high cut clew to make life easier on the foredeck for anchoring or picking up a mooring under sail and for MOB drills.
• I wanted tell tails and camber stripe for teaching purposes.
• I wanted a UV strip and anti flutter line on leech and foot.

My sailmaker managed to achieve all this and the end result can be seen in the next photo.

I am not sure whether it is a blade jib with a high clew or a furling yankee or a full luff length working jib but whatever it is called it certainly works.

With this working headsail the full mainsail can be kept further up the wind range and hull speed is achieved at the bottom of a force 4. As the wind rises both mainsail and headsail can be gradually reduced in size. With several rolls in this headsail a very flat and efficient shape is maintained due partly to the design of the sail and partly to the inclusion of a foam luff.

During my summer teaching cruises of the Scottish Hebrides Westbound Adventurer has achieved some very fast windward passages. These have been faster than the target speeds for the windward legs of the Sigma 33 racing fleet. I claim no credit for this.

The 3 people who deserve the credit are

• David Thomas for designing such an efficient and easily driven hull with a fine entry forward.
• Chris Owen my sailmaker for the excellent design and construction of this working headsail and fully battened mainsail.

• Warwick Collins for designing the Tandem Wing Keel which was fitted by the first owner of my yacht.

More about this keel in a future article but I believe that it contributes to windward performance in a seaway.

In conclusion then, the use of both these headsails within the context of a 5 day RYA Course leads to discussion about the advantages and disadvantages of each system. The novice is busy coming to terms with head, tack, clew, luff, leech and foot. For the more experienced, discussion leads to headsail shape, VMG and more. This is what sail training is all about and I am happy to take some credit for this!

In next month’s article I drag the 3 remaining headsails from their locker and examine their specialised use.

 

Anchoring Under Sail

Do it under sail because it has all been done before. It only takes a bit of thought and preparation. My previous articles in this series have been very analytical. In this final article I become a little anecdotal to make the point.

About 30 years ago as a member of a Clyde based yacht club, I was attending a social function. I had recently returned from my first visit to St.Kilda as a crewmember on a large yacht. I was very animated recalling the highlights of my visit while a quiet and unassuming man in the company prompted me with a few questions. I realised that he must have had his own St.Kilda experience and later that evening as the numbers in the clubhouse diminished, I was able to ask him some questions.

“When were you last there?”

“A very long time ago.”

“Where did you leave from?”

“The Sound of Harris”

“How many of you were there on board?”

“Just me”

His reply to my last question left me speechless: “What size was your yacht?”

“Oh, it was just my 16 foot Wayfarer. I had to hang about a while for a weather window but it was fabulous fun!”

About 25 years ago as a novice skipper on my first sailing holiday in the Med we were the last boat to leave our lunchtime anchorage. It was day one and we were about to pay the price for over running the lunchtime swim and siesta. As the rest of the fleet headed into the distance I realised that we could become the classic last arrival entertainment, prior to the evening meal ashore. The flotilla skipper had briefed us that very morning about Mediterranean mooring and the lead boat gave a perfect 2 handed demonstration. The stern anchor was dropped 3 boat lengths from the jetty by the flotilla hostess and with one hand on the tiller and one hand on the anchor warp the flotilla engineer brought the boat to a stop as the hostess calmly stepped 12 inches from bow to jetty with the shore lines. With the engine running slow ahead the engineer strolled from cockpit to foredeck to adjust the inboard end of the mooring lines as the hostess made them fast ashore. The flotilla skipper had told us not to worry if we didn’t get it right first time. The lead boat would be there ahead of us to guide us through the process.

I started the engine to depart our lunchtime anchorage and one of my 3 crew prepared to lift the hook but something odd was happening, or rather, not happening. It took a while to figure out that the prop was not turning. I called the lead boat on the VHF. The flotilla skipper consulted the flotilla engineer and we were asked to sail towards our evening destination and give them another call when we were a mile off. We had not dug the anchor in very well as it was a short stop so it came up with 2 of us heaving on the cable. We managed to set sail before we drifted ashore and headed off in pursuit of the rest of the fleet. About 2 hours later we called again requesting a tow into the tiny harbour so that we could safely join the rest of the fleet all tied up at the shoreside restaurant. The reply was that the engineer had been called away on personal business and we should keep sailing towards the harbour entrance and await further instructions. We were to roll away the furling headsail and drop the mainsail outside the harbour and have another attempt at starting the engine. The engine duly started but the prop still refused to turn. We were now instructed to prepare an anchor on the bow, unroll half of the headsail and slowly drift into the harbour in the light onshore wind that was blowing. We were asked if we could see the flotilla hostess waving at us at the end of the row of berthed boats. She had some cold beers in one hand and was pointing at a very small parking space with the other hand. The rest of the fleet were of course sitting in comfortable chairs well into their second round of drinks outside the restaurant. “On my command turn into the wind and roll the headsail away. When the boat comes to a stop drop the anchor.” As we came abeam of the flotilla hostess we got the command and did as we were told. The yacht was now at anchor about 4 or 5 boat lengths off the jetty with the stern pointing at the hostess. We were about to get into the dinghy and row ashore to collect the beers but the flotilla skipper had other plans. “Get the fenders on starboard side. Get mooring lines ready on stern. Let out the anchor cable.” We did all that and stopped one boat length short of the jetty. “Tie a mooring line onto the bitter end of the anchor cable and let out again.” As we slid backwards into our berth we got a round of applause from the rest of the fleet. The next morning the engineer fixed the cable linkage which had come adrift at the gearbox. As a novice skipper that was a very eventful day one. The rest of the week was plain sailing.

About 10 years ago I ran an “over the top” RYA Course from the Western Isles to Inverness via the Orkney Isles. At the time I thought it was adventurous and that was what my trainees had signed up for. While tied up in Stromness Harbour I noticed a single hander slowly tack his 27 foot yacht all the way into the inner harbour. I took his lines and helped him tie up alongside Westbound Adventurer. My first question was “Engine failure I assume?” The reply came back “Don’t have one to fail.” My second question was “Where from?” The reply came back “Oslo.”

Later that evening over a wee dram he explained that he was a schoolteacher from Norway on a sabbatical year and was sailing from Oslo to the Med via the Orkneys and hoped to take in the Western Isles on his way south. He pulled out some small scale charts of the Western Isles and asked me if I could recommend any good anchorages. His philosophy was that he was not in a hurry and that installing an engine would give him too many headaches.

About 5 years ago we motored into Puilladobhrain and dropped anchor several times to give the Comp Crew trainees a turn at the sharp end and the Day Skipper trainees a turn at making decisions from the helm. By the time we finished an hour or so of manouvres the anchorage was starting to fill up as it does in the summer months. We had just settled down to drinks in the cockpit when one of my trainees pointed to a yacht “Sailing through that narrow gap!” I explained to my trainees that the yacht was coming in on a safe beam reach at slow speed and that the skipper would probably have been here on previous occasions. What happened next was a lesson for us all.

As the Rival 32 came closer we could see that the anchor was already hanging from the bow roller but there was no crew on the foredeck. As the yacht entered the main pool the headsail was furled away and the yacht manoeuvred through the anchorage under main only. As the bow was brought head to wind the person on the helm walked slowly from cockpit to foredeck. The timing was perfect. As he reached the anchor cable the boat was dead in the water. Down went the hook and the cable was slowly paid out and snubbed off several times. This single handed yachtsman had obviously done it all before. It was another 20 minutes or so before he dropped the main. He sat in the cockpit puffing on his pipe checking that the boat was holding. It was a great lesson in preparation.

If you havn’t dropped anchor under sail before here is the analytical bit:

When preparing candidates for the 8 hour Yachtmaster Offshore Examination I explain that they will have to demonstrate their ability to handle the boat under sail in a close quarter situation. The examiner may request a particular context for this or may give the candidate a choice. I tell people that dropping anchor under sail is easier than doing a MOB under sail or picking up a mooring under sail. In the second and third context you need to stop the boat close to the MOB or within a boat hooks length of the mooring buoy. When dropping anchor under sail there is usually a much wider spot in which you can drop the hook.

The single hander in Puilladobhrain did a “reach and point” to kill the boat speed and got it spot on because he knew his own boat so well. A more controlled way of making the final approach to the spot where you want to drop the hook is by spilling and filling the main with the boat at 60 degrees to the apparent wind. If you have a fully battened mainsail you might need a final luff up to kill the speed or you could try scandalising the main. Remember to release the kicker and mainsheet fully before pulling hard on the topping lift if you are going to scandalise. Whatever method you use the hook goes down when the boat is dead in the water and the cable is gradually let out and snubbed off as outlined in my April article. Don’t drop the main until you are happy that the anchor is holding. To dig it in walk forward of the kicking strap and pull the main towards the shrouds. This may have to be done several times on alternate sides of the boat. As you back the main watch the anchor cable to see if it comes under tension.

If you havn’t tried sailing the anchor out give the following a try and see how it works:

• Hoist the main but keep the sheet and kicker loose and warn everyone that the boom may be swinging about.
• If the wind is very light and you have one or 2 crew who want some exercise you could haul on the anchor cable until it breaks out then sail away. If the anchor needs a nudge to break out try backing a bit of headsail.
• If the wind is anything more than very light try short tacking towards the anchor but tell the person or persons at the sharp end not to haul in the slack on the cable until after each tack.
• To short tack towards the anchor you will usually need some headsail but keep the headsail small as a large one will foul with the foredeck crew and they will not be happy!
• If you are trying this for the first time it makes sense to do it in a spot where there is plenty of searoom.

The accompanying photo was taken on 25 July this year. The Clyde Cruising Club were at a high point in their Centenary Celebrations in Vatersay Bay. 100 years ago the visiting herring fleet would come here in May or June each year. They had no engines, no GPS or chart plotter. They sailed of course and would hove-too in safe water until a local boat came to pilot them in. The anchor would be dropped and lifted under sail as readily as we start and stop our inboard diesel engine.

Why call them Atlantic Islands when the Monachs, Flannans, and St.Kilda are 5, 15 and 43 miles west of the nearest point on the Outer Hebrides? If you could launch a fast inflatable from the nearest beach on the Western Isles you could be there in a jiffy. There are however very few days in the year when you could take off from an Atlantic beach and have a flat water passage to these islands.

For the cruising yachtsman the Monach Isles are 35 miles from Eriskay or Northbay via the Sound of Barra or 30 miles from Loch Maddy via the Sound of Harris. If conditions favour an overnight anchorage at the west end of the Sound of Harris, the distance to the Monachs could be reduced to about 20 miles. The commitment is not as great as that required for St.Kilda, and there is a choice of anchorages marked on the sailing directions. I would urge caution with the anchorage in the south bay as it is surrounded with rocks and requires a very careful approach, even in settled weather. If the wind is favourable go for Croic Harbour on the NE side of Ceann Iar. The Monachs are best enjoyed in settled weather. A bad weather escape to the north or west of the Monachs would involve dodging various outlying reefs. There is no detailed chart available for the Monach Isles but copies of a survey by Captain H.C.Otter dated 1860 can be obtained from the National Library of Scotland for a very modest sum. The attention to detail is amazing with the magnetic variation at 27-5 degrees west in 1861 decreasing 6-5 degrees annually!

For the Cruising yachtsman the Flannan Isles are only 15 miles west of Gallan Head which is fine if you are departing from Loch Roag. From Stornoway, over the top of the Butt of Lewis the distance is 70 miles and from Loch Maddy via the Sound of Harris it is 45 miles. The accompanying photos clearly illustrate that there is considerable risk in going ashore in anything other than very settled conditions. The bottom is rocky making it unwise to leave a yacht unattended, even in the best conditions. Given suitable conditions, a visit to this historic place (where 3 lighthouse keepers disappeared in 1933) is very worthwhile.

For the cruising yachtsman it is the St.Kilda group of islands which have the greatest attraction. I believe it is a combination of their remoteness, their history and the sheer physical grandeur of the highest sea cliffs in Britain which draws us so far west. Add to this the drama of the sea stacks and the colonies of birds and we run out of excuses for not going. It is however not so easy to get there. It is more difficult to get there and to spend time ashore. It is much more difficult to get there, to spend time ashore and to get back to the east side of the Outer Hebrides in comfort.

There is only one good anchorage which is in Village Bay on the main and only inhabited island of Hirta. This anchorage is open to swell from the southwest to northeast and as the sailing directions wisely tell us, we need to be prepared to clear out at short notice. Some thought should be given to what clearing out of St.Kilda actually means. If the wind is NE it is unlikely that we shall make the 45 miles to the Sound of Harris in one tack so we may decide to reach the 60 miles to the Sound of Barra. Depending on our E.T.A. at the Sound of Barra we may have to stand off until dawn or put in an extra 25 miles to take us safely round the bottom of Barra Head and up into Vatersay or Castlebay. This may be a piece of cake if we have a strong team of competent helmsmen on board but if we are shorthanded and have spent 12 hours getting to St.Kilda we need a rest when we get there. We may not get a rest if a change in wind direction dictates that we clear out of Village Bay.

If a southerly wind dictates that we clear out we can make the Sound of Harris in one tack but what about a southeasterly? We may be comfortable in Village Bay in rising winds from the SW to N but as we rest from our outward passage then spend time ashore the Atlantic swell has been increasing. We may have a following wind for our return passage but will it be safe to enter the Sound of Harris as a lee shore even in good visibility? Will we be forced to run 75 miles to either end of the Outer Hebrides plus a further 15 down to Stornoway or 12 up to Castlebay? How much offing should we give the Butt of Lewis or Barra Head?

There is one possible alternative to clearing out of St.Kilda but it is not without its own risks. Glen Bay is on the opposite side of Hirta to Village Bay. It is deep for anchoring except for very close to the shore and the quality of the ground is doubtful. A line ashore could be set up as the wind funnels down the hillside overlooking this bay and would hold the yacht offshore. The risk is that the wind might change direction and put the yacht ashore. There are 2 possible precautions against this risk. An angel could be lowered from the stern and the line brought forward to the bow so that the line would not snag on the rudder or keel. (My own preference would be to drop the line from the bow.) A second precaution would be for an anchor watch if a change of wind direction is anticipated. Another consideration is that Glen Bay puts us outwith VHF coverage in an emergency but faced with a long return passage a few hours rest for a tired crew can make a difference.

I would suggest that a minimum of 48 hours settled weather is needed for all but the strongest crews. It’s a great pity to rush out to St.Kilda and to have to rush back again. A sail around the islands, especially between Stac Lee and Boreray is something that will be remembered for a life time. I have been running teaching cruises of the Outer Hebrides in July and August for several years and passages to St.Kilda have been attempted on about 50% of these cruises. Before people sign up for these teaching cruises I emphasise that they are cruises of the Outer Hebrides and getting to St.Kilda should be regarded as a bonus. The perfect wind for getting there, for resting there and for returning would be a light to moderate northerly wind assuming a departure from the Sound of Harris. For a departure from Barra a light to moderate southwesterly would be great providing it veers while we are there and stays west to north for our return. This, of course, is a dream world. Reality is different. We juggle time, distance, weather with accurate and not so accurate forecasts, crew strength, reserves of water and fuel.and sometimes we go for it, sometimes we don’t. There are a few occasions when it all fits perfectly into place and we are left rejoicing on the western edge of the Western Isles. The best way to conclude these 4 articles about the Outer Hebrides is to leave you with the log of one such occasion.

To fully explore the delights of the Scottish Hebrides we need the confidence to anchor in gale force winds. The good news is that summer gales are usually well forecast and short lived. Your first experience of gale force winds at anchor will cause you some anxiety. It is only by doing it for real that you loose your natural anxiety and gain confidence in your ground tackle.

If you are cruising the Inner Hebrides you don’t have to retreat to Tobermory just because it’s going to blow up for one night. You could retreat to Arisaig or elsewhere and find all the swinging moorings occupied so it makes sense to be prepared for anchoring in a blow.

Westbound Adventurer is often at anchor in winds of over 30 knots and every summer in recent years has had 3 or 4 nights with winds over 40 knots and maximum gusts up to 60 knots. I have asked 2 cruising couples about their experiences at anchor in the Scottish Hebrides because they have more miles under their keel than I have.

Norman and Gillian Smith have over 40 years quality experience but cannot identify a particular month as having typically settled or unsettled weather. They are prepared for strong winds at any time. In a good sheltered anchorage they regard 40 knots of wind as only a problem for getting ashore in the dinghy. Their maximum gusts have been 74 knots in Loch Seaforth in June 2000 and 70 knots in Loch Skipport in June 2002. They reminded me that the only dependable factor is the amount of daylight and a gale during the day is never going to be as worrying as a gale in darkness. They have a particular interest in the west coast of Lewis and Harris and found something interesting in an obscure anchorage near Brenish. See attached photo!

John and Helen Anderson have been cruising the Scottish Hebrides in summer and winter for many years and have captured some fabulous images, some of which can be seen in the Clyde Cruising Club’s Sailing Directions for the Mull of Kintyre to Ardnamurchan. To mark their centenary year the CCC have a new publication, “Cruising Scotland” available in June which features many more of John’s images. John tells me that in 2000 he was lying to a single Delta anchor in Northbay, Barra. The weather was wild, with the surface of the sea being whipped off and their handheld anemometer was off scale at the top of force 9. When the wind eased, John checked at the nearby weather station at Barra airport. It had recorded the highest hourly average as 54 knots, with gusts up to 83 knots. John says that this suggests the Delta is an excellent anchor and that the holding in Northbay is superb. He has since moved to Spade anchors that he believes are even better.

Both couples agree with me that the most important issue is to head for shelter in relation to the forecast wind direction. It’s less stressful if you can arrive at your chosen location before it blows up. For cruising Scottish waters we are blessed with 2 excellent sets of Sailing Directions. Those by Martin Lawrence are published by Imray. Various people have contributed to those published by the Clyde Cruising Club. The current editor is Edward Mason. Many cruising yachtsmen keep both sets on board.

For much of the time one anchor well dug in is sufficient but how hard do we have to dig it in to replicate the full force of the winds that are forecast to hit us in a few hours time? If you are uncertain about whether your anchor is going to hold or drag you will have a stressful night. At best you will have lost sleep and at worst you might have a dangerous nocturnal battle with a dragging anchor at the height of the gale.

As a sailing instructor I cannot afford to loose sleep as I will not function properly the following day if there has been an epic the previous night. Some years ago I invested in an instrument which measures tension on the anchor cable “Anchorwatch” and over a period of time I built up a profile of Westbound Adventurer at anchor in different wind strengths and also tested the strain of the cable when running the engine astern at various revs. Anchorwatch records the peak load as well as the current load and my masthead wind instrument does the same. This meant that it was not necessary to stay awake all night in the interest of science! The photos and results are self explanatory but valid only for Westbound Adventurer.

These figures are lower than others produced and published for a 10 metre yacht. I believe that data from other sources are based on windage factor formulae rather than observation. The highest shock loads will not have registered with my observations on Westbound Adventurer because of the amount on nylon I deployed when using Anchorwatch. The designer of Anchorwatch, John Knox, has another means of estimating anchor cable tension which involves careful marking of a calibrated length of nylon. If you want to investigate this low tech method contact John at Knoxjohnh@aol.com

When anchoring for a blow I use the maximum scope possible with a cable of chain and warp and very gradually build up the revs astern on the engine. I know that full revs astern is about the equivalent of a F8 wind with gusts up to F9. This is only valid in a sheltered anchorage where pitching is not an issue. If I am anchoring in a familiar spot I sleep. If it’s an unfamiliar spot I could test the hold up to the equivalent of a F10 gusting 11 by motoring forward until there is slack on the cable then going astern to produce a jerk stop when the cable comes up tight.

If the anchor is not holding now is the time to select another spot and do it all over again. It may be time consuming but better now than in the dark in the early hours at the height of the gale. If after several attempts with a single anchor at maximum scope I am not confident about the holding I would put a second anchor and cable down. If any doubts still remain with 2 anchors down I would consider setting an echo sounder alarm if the shape of the seabed allows. A GPS radius alarm could also be used depending on the size of the anchorage. The last thing I want to do is to organise anchor watches by the crew in the cockpit but as a last resort it is better to do that and be ready to clear out and ride out the gale at sea rather than drag onto rocks.

The above is a suggested sequence of events if you need to be prepared for the worst case scenario. In practise I often put a second anchor down for training purposes even though I know a single anchor will hold. There are 3 possible techniques which I have used but I would be interested to hear from any yachtsman who has used another method.

In all cases the first anchor needs to be as well dug in as possible on a cable of chain and warp at maximum scope. It is very useful to put a marker buoy on the crown of the first anchor so that you have a reference point for dropping the second.

 

• If you are in the chosen anchorage before it blows up the dinghy can be used to drop the second anchor and it is a lot easier if there are 2 people in the dinghy. The hardware needs to be organised on the floor of the dinghy with the anchor on top ready to drop, the chain next so that it can be paid out as you drift downwind, and the warp last so that it can be taken back to the yacht when the hardware is on the bottom. It is also very useful to have a marker buoy attached to the crown of the second anchor.
• A second technique is to fall back on the full scope of the first cable or possibly add an extra warp to this cable as a temporary measure. With the second anchor and cable prepared on deck motor towards the chosen spot to drop the second anchor (with a marker buoy attached to its crown) and fall back on the second cable. While this is being done someone needs to keep an eye on the first cable in case it snags on the yacht. The bitter end of the (extended) first cable could come into the cockpit and be taken in and fed out as required while the second anchor is being deployed. Obviously good communication all round is important.
• A third technique is to buoy and dump the bitter end of the first cable then motor towards the chosen spot to drop the second anchor and cable and dig it in as if it were a single cable. Using an extended warp (if required) motor over to the bitter end of the first cable and collect it.

Whatever technique is used both cables need to be adjusted by trial and error until the yacht is lying equidistant between the 2 anchors as illustrated in the sketch. This is best achieved with 2 people on the foredeck adjusting the warp of each cable led through the port and starboard fairlead rather than both through the bow roller.

Lying to 2 anchors in the “Fork moor” as illustrated in the sketch reduces the distance the yacht will yaw or swing from side to side compared with lying to a single anchor. After much trial and error I now recover 2 anchors separately by buoying and dumping the bitter end of one cable but don’t loose sight of the cable you have dumped! I am reluctant to deploy 2 anchors if the wind is forecast to shift as it can take some time to untangle the cables next morning.

Some experienced yachtsmen favour attaching a second anchor to the first on a single cable. Some believe this is a good practice only if there is a length of chain between the crown of the inboard anchor and the shank of the outboard anchor. Some experienced yachtsmen believe the practise of tandem anchors on one cable is very dangerous. The jury is out but I don’t know if a verdict will ever be reached. Research needs to be done on the merits and demerits of tandem anchors but I have so far failed to convince the authorities that there is a need for money to be spent on researching this topic. To date I am aware of only one MAIB accident report following a mishap to a yacht with tandem anchors on one cable. I would be very interested to hear from any yachtsman with good or bad experiences with tandem anchors.

If you are shorthanded and the process of setting a second anchor is daunting there is the possibility of taking a line ashore as a back up to a single anchor. The success of this is dependent upon:

• Being able to anchor close inshore
• Having a warp of sufficient length and suitable hardware for an attachment ashore
• Arriving in the anchorage while conditions are safe to go ashore and return to the yacht.

What about beefing up a single cable by sending an angel down? I think I shall leave that one till next month as the issues are complex. I shall also look at riding sails, and take a closer look at shorelines.

You are probably not going to sleep well during your first night at anchor in gale force winds because the noise and vibrations on the boat can take a bit of getting used to. The boat can surge back in strong gusts particularly if you get a violent downdraft from a nearby mountain. The second and third time you anchor in gale force winds you will be much more confident about the holding power of your own ground tackle. Ear plugs are useful. Sleep well!