Will Burton explains how preparing your yacht for the worst-case scenario can help you stay afloat for longerThe Catalina 41 Coolabah sank within hours of striking an object in the Pacific. Photo: John JenningsTwenty miles south of Salcombe, in deteriorating weather, Timothy Meo realised that the new 36-footer he was helping to deliver to the Solent was sinking. \u201cThe engine compartment was flooded with a lot of water. Initially neither of us could tell where it was coming from.
\n\u201cWe found the rate of ingress reduced when we were making way, so we changed course towards Salcombe, made a Pan Pan call to Falmouth Coastguard and switched on the yacht\u2019s two electric bilge pumps \u2013 neither of which appeared to be working.
\n\u201cWe took turns on the manual pump, which did work, but it was exhausting. The Coastguard were keen to send out a lifeboat, but after some time pumping, we eventually felt we were keeping up with the water coming in; so we declined their offer and pressed on.\u201d
\nThe deeper the hull breach, the more water is forced in. A 5cm (2in) diameter hole 30cm below the water will let in 11,000 litres in one hour. Move that hole down to 1m, and 20,000 litres of water will flow in
\nThe yacht reached Salcombe safely and the source of water ingress was found to be an incorrectly installed wet exhaust system. Meo is philosophical about his near sinking experience. \u201cWe had a thorough handover from the yacht builder, a reputable company, and left with no reservations about making the passage.
\n\u201cThe assumption that a brand new boat is safe, though, is a dangerous one. We later found that the electric bilge pumps didn\u2019t work because they were clogged up with shavings and dirt from the build process. A high pumping capacity, that\u2019s been thoroughly tested, is absolutely essential. The boat being a unique design certainly contributed to the \u2018unknowns\u2019 about it. All of us learned from the experience, including the manufacturer. It could have been much worse.\u201d
\nWhile it is rare, but not impossible, for a yacht\u2019s hull to fail, mechanical failure is a more likely cause of sinking on a modern yacht. David Greening, a small craft surveyor, explains: \u201cIn a modern GRP yacht, the first three things I would always look at are mechanical.
\n\u201cOne: the condition of the propeller shaft seal. Two: the rudder stock, and three: the keel. Looking at both the fastenings and supporting structures. Failures in these three areas are the most likely points of failure, which can be caused by poor design or maintenance.\u201d
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\t\t\t\t\t\tThree crew and two children rescued in the Atlantic from sinking ARC yacht<\/p>\n
\t\t\t\t\t\t\tA crew of five taking part in the ARC transatlantic rally has been rescued after their yacht began sinking yesterday.\u2026<\/p>\n
\t\t\t\t\t\tMayday, we\u2019re sinking \u2013 crew rescued from the ARC yacht Magritte as she goes down<\/p>\n
\t\t\t\t\t\t\tEarly evening on 3 December Steve Arnold was awoken by his friend and crewmate Andy Mills, who had noticed water\u2026<\/p>\n
As yachts have become more comfortably equipped, the number of seacocks has increased. With each comes an inherent point of weakness. \u201cThey should be inspected annually for signs of corrosion, rust and dezincification. The hoses should be double jubilee-clipped and have tapered soft-wood plugs in case they fail,\u201d adds Greening.
\nSo what should you do if you find your yacht is taking on water? First, you should try to determine where it is coming from. Second, reduce the rate of ingress. And third, get the water that has come in back out: in the most efficient way possible.
\nThese fundamentals of damage control are something taught to every sailor at the Royal Navy\u2019s Phoenix Damage Control Instructional Unit in Portsmouth. A multimillion-pound sinking ship simulator where all Royal Navy personal are trained, very realistically, in the fundamentals of how to stay afloat. Whilst there are some differences between a steel warship and a sailing yacht, they are battle-tested principles that can be used on any boat.
\nA manual bilge pump with good leverage is a useful addition, but what is your yacht\u2019s overall pumping capacity?
\nLieutenant Rob Manson, who runs the training facility, explains that they teach sailors to think and act fast. \u201cWith every minute that passes, the situation becomes more complicated. The more water that\u2019s in the hull, the more unstable the vessel can be and the more likely it is to capsize. What we teach is a relatively simple skill set that can be put into practice almost anywhere on board. The training is conducted in seawater, so it focusses the mind!\u201d
\nWhat equipment to have on board a yacht to stop it sinking is something that\u2019s best decided after considering what a sinking might actually entail. Sailing rally safety checklists usually include soft wooden plugs for all seacocks, as well as manual and electric bilge pumps \u2013 all sensible things to have on board.
\nHowever, in recent years the number of yachts that have run into submerged objects, including whales and shipping containers, has increased significantly, posing the question: is being \u2018holed\u2019 likely to mean a round hole or more of an irregular gash.
\nOnce floorboards and stores are floating \u2013 as here on the yacht Magritte shortly before she sank in 2016 \u2013 finding and tackling a leak becomes near impossible
\nOne particularly impressive product is Stay Afloat \u2013 a flexible waterproof putty that can be jammed into the most inaccessible points and has proven itself to be highly effective.
\nIt can be jammed into a failed stern gland, or seacock, seal along the line of a gash in the hull, or in conjunction with other materials found at hand.
\nThe stern gland remains an Achilles Heel of modern yachts, explains Vyv Cox, a professional yacht engineer. \u201cOne of the largest holes in the boat, through which water might penetrate, is the stern tube through which the propeller shaft passes.
\nThis has traditionally been sealed by a packed gland consisting of three or four turns of a woven flexible material such as graphite-impregnated cotton or PTFE. This design is reliable and rarely causes major leaks on failure, but it does have some disadvantages, resulting in the emergence of several patent seal designs.
\nIn the vast majority of cases these are highly reliable and overcome the drips and need for greasing of the traditional type, but their failure can result in considerably greater influx of water.
\n\u201cOriginally, traditional gland types were solidly attached to the tube but the advent of flexible engine mountings dictated that the gland also needed to accommodate shaft movement by being mounted on a length of rubber hose. Fracture or loosening of this hose is potentially the greatest source of leakage.
\n\u201cPacked glands can be over-tightened quite easily, leading to [the hose\u2019s] disintegration. In some cases there are \u2018dogs\u2019 on both the stern tube and gland housing to prevent this. Most patent seal designs, exert far lower frictional drag, making this failure type less likely.\u201d
\nIf circumstances allow, stopping water coming in from the outside of the hull is likely to be more efficient as the water pressure is working with you, not against you. For this, a sail or piece of PVC matting stretched over the hole can prove effective, but only if it can be firmly held in place.
\nUnder-bunk boards were cut, glued and drilled into place underwater on the catamaran Ensemble after she was holed
\nEven better is a combination of wood, Stay Afloat, and screws, which can be put together to fashion a serious patch. The essential tool to carry to make this work is an old fashioned hand drill, usable underwater, albeit slowly.
\nThis solution carried the catamaran Ensemble over 800 miles when it was holed on a remote Pacific atoll while at anchor. Nearby cruisers came to Ensemble\u2019s assistance, including retired engineer Ed Butt, who helped fix a piece of wood to the outside of the hull by diving underwater and driving fixings through the hull.
\nInterior access to the hull is another consideration, particularly when buying a new yacht. Some modern moulded interiors actually make it quite difficult to get to parts of the hull that might be holed, so the means to break through the interior quickly is an additional consideration. A weighty axe is carried by many offshore cruisers for this purpose.
\nAn engine driven bilge pump, common on fishing boats, can shift a large quantity of water and isn\u2019t dependent on battery power
\nModern yachts are usually equipped with both electric and manual bilge pumps, but surveyors often remark that electric pumps are poorly installed, meaning they are inefficient, while manual pumps would be of little use in an emergency. The sums make difficult reading for anyone with only a standard sized pump on board.
\nA hole 2.5cm in diameter, 30cm under the waterline, will let in 2,700 litres of water per hour. A 5cm hole in the same position will let in 11,000 litres. Most underwater collision damage occurs even deeper, meaning an even faster ingress of water.
\nBeing able to pump out a large volume of water won\u2019t save your yacht on its own, but it might just buy you enough time to affect a temporary repair, or abandon the yacht in a controlled way. So how do you go about increasing your yacht\u2019s pump-out capacity significantly?
\nSomething that\u2019s common on even small commercial fishing boats is a main engine-driven bilge pump. Not reliant on electrical power to run (your yacht\u2019s batteries could quickly find themselves underwater) and with a very high pumping capacity when compared to an electric pump, they operate directly from the engine.
\nAnother option is fitting an oversized electric pump that\u2019s rated for continuous use, or better, having one you can deploy quickly in any part of the boat on a long lead. Another tool Ed Butt used, two 4,000 gallon per hour (gph) pumps strapped together, made an enormous difference, buying enough time to make repairs with help from others in the same anchorage.
\nTwin 4,000 gallon per hour pumps kept water ingress at bay for long enough to effect a sturdy repair on Ed Butt\u2019s catamaran Ensemble
\nThe obvious and unexplained
\nDespite our best efforts, incidents in the past, such as the unexplained sinking of ARC yacht Magritte in December 2015, demonstrate that well prepared and equipped yachts can and do sink without explanation.
\nIn parallel, the risk of hitting a semi-submerged object, such as debris, sealife or a shipping container, would appear to have increased. So while preparing your yacht to avoid sinking, consider making preparations at the same time to abandon in a matter of seconds rather than minutes.
\nPan Pan or Mayday?
\nIn the event of finding out that you are taking on water, letting the Coastguard and other yachts know about your situation is wise. A Mayday should only be used if life is in \u2018imminent danger.\u2019 If you are sinking rapidly and anticipate abandoning the vessel very soon, send a Mayday.
\nA Pan Pan says \u2018it\u2019s serious, we need help, but there isn\u2019t a grave or imminent danger to the boat or those on board\u2019. Should things deteriorate rapidly, they will already have information about your position and situation.
\nFinding the source of a leak
\nIf you are sinking, locating where the water is coming from can be challenging, particularly if the source is below the waterline.
\nFirst check that it is definitely seawater. A failed hot water tank valve on a larger yacht will result in a lot of water in the bilge! While it\u2019s not generally advisable to taste bilge water, in an emergency, this is a quick way of determining whether it\u2019s salty or fresh.
\nWork logically through all of your boat\u2019s through-hull fittings from bow to stern. A laminated diagram should be kept with the yacht\u2019s documents. Be sure to include the stern gland.
\nPump as much water out as possible, this may well reveal where the water is coming from.
\nAbout the author
\nWilliam Bruton, 27, grew up in Lancashire and learned to sail in 2012. He now works as a freelance skipper all over the world, specialising in Oyster yachts.
\nFirst published in the August 2017 edition of Yachting World.
\nThe post How to stay afloat: Top tips for rescuing a sinking yacht appeared first on Yachting World.<\/p>\n","protected":false},"excerpt":{"rendered":"
Will Burton explains how preparing your yacht for the worst-case scenario can help you stay afloat for longerThe Catalina 41 Coolabah sank within hours of striking an object in the Pacific. Photo: John JenningsTwenty miles south of Salcombe, in deteriorating … <\/p>\n