Heavy Weather Tactics Offshore - Sea Anchors, Drogues & Storm Sails

Prerequisites

This lesson assumes you hold, or are at the standard of, RYA Coastal Skipper, and have completed the Yachtmaster Offshore lessons on passage planning and ocean meteorology. In particular you should be able to:

• Reef the main and headsail quickly, by day and by night, on the boat you sail.
• Heave-to in moderate conditions.
• Interpret forecasts and gale warnings, and recognise the signs of an approaching depression.
• Rig jacklines and use lifejackets and tethers correctly.
• Carry out man overboard recovery under sail and power.

Qualifying sea time for the Yachtmaster Offshore exam (2,500nm, 50 days, 5 passages over 60nm) should ideally include some experience of strong winds, so you can speak from experience about how your boat behaves.

Learning Objectives

• Cover the RYA Yachtmaster Offshore syllabus items for heavy weather: preparation, storm sails, heaving-to, running off, drogues and sea anchors, knockdown recovery and tactical choice (see the Syllabus Map).
• Explain wave height, period, steepness and breaking, and why wind against tide or shoaling is dangerous.
• Understand stability curves, the angle of vanishing stability and design categories.
• Explain why early preparation matters more than any single storm tactic.
• Prepare the vessel below decks, on deck and aloft for heavy weather, and prepare the crew.
• Rig and set a trysail and storm jib, with correct sheet leads.
• Describe and carry out heaving-to, and explain how it behaves on different hull types.
• Explain the dangers of lying ahull.
• Run off safely, controlling speed by sail area, warps and drogues.
• Explain the difference between a sea anchor and a drogue, including the series drogue, and how to deploy and recover them.
• Respond to a knockdown.
• Choose a tactic based on sea state, sea room, boat and crew.

Syllabus Map

This lesson covers the heavy weather and storm tactics items of the RYA Yachtmaster Offshore syllabus (shorebased and practical), and supports the Yachtmaster Ocean oral.

At Yachtmaster Offshore standard the examiner will ask you to explain why you would choose a particular tactic in specific conditions, not just describe one. Your answers should state conditions, sea room, boat type and crew state.

What Is Heavy Weather?

There is no single wind speed at which "heavy weather" starts. It depends on the boat and crew: Force 6 can be heavy weather for a 9m yacht with a novice crew, while Force 8 may be manageable for a well-sailed 15m yacht with plenty of sea room. What makes conditions dangerous is mainly the sea, in particular breaking waves. A boat can cope with high winds in sheltered water; it is the breaking crest that knocks it down.

Heavy weather offshore is not rare. Over a sailing career it is inevitable, which is why the RYA treats it as core Offshore competence. Most heavy weather damage and injury is caused by being unprepared rather than by the wind itself.

Preparation: Before the Wind Arrives

Prepare when the forecast or barometer first suggests strong winds, not when it is already blowing. It is far easier, safer and quicker to secure a boat in Force 4 than in Force 8.

Below decks

When the boat heels beyond 30 degrees or drops off a wave, every loose item becomes a projectile. A tin of beans or a toolbox flying across the cabin can break bones or knock someone unconscious.

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1. Stow everything: lock lockers, fit fiddles, wedge loose items. Secure the cooker and set the gimbal locks as appropriate.
2. Screw down or tape floorboards; check that the batteries, anchor chain and heavy tools cannot move, even in a knockdown.
3. Rig lee cloths on every bunk in use.
4. Pump the bilges dry, check the bilge pumps work and the strum boxes are clear, and know where the manual pump handle is.
5. Close and dog all hatches and portlights. Close seacocks that are not needed (heads, sink outlets on the lee side).
6. Fit washboards, and have a lanyard on them so they cannot be lost.
7. Prepare food and hot drinks in flasks before conditions deteriorate. Put seasickness tablets where they can be reached.
8. Get the grab bag, flares, handheld VHF and EPIRB to a known accessible place.
9. Check the navigation: fix the position, note the course to the nearest sea room and refuges, and update the log.

On deck and aloft

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1. Remove anything that can be taken below, such as cockpit cushions and loose lines. Lash everything that must stay on deck: dinghy, liferaft, jerry cans, spinnaker pole.
2. Rig jacklines from bow to stern on both sides, so crew can clip on before leaving the companionway and stay clipped on all the way forward.
3. Check the rig: cotter pins, shackle mousings, chafe on sheets and halyards, and the reefing lines.
4. Get the storm sails out and on deck, and rig the inner forestay if needed, before they are required.
5. Reduce windage: remove dodger panels if they are likely to be damaged; lower and lash anything that can flog.

The crew

• Brief everyone on the plan, the expected conditions and what tactic you intend to use.
• Everyone wears lifejackets and tethers on deck. Clip on before leaving the companionway; use short tethers in the cockpit so that a fall cannot carry you over the side.
• Reduce the watch on deck to the minimum needed, and rest everyone else. A watch of two in a gale, rotating frequently, is better than four exhausted people on deck.
• Feed everyone before it gets rough.

Reefing early

Reef when you first think about it. A reef that turns out unnecessary costs a little speed; a reef left too late can mean a broach, torn sails or crew injured on the foredeck. A simple standing order: reef at a set apparent wind speed for each reef, measured on the boat, not at a Beaufort force from the forecast.

Waves and Why They Break

Understanding waves is essential to choosing a tactic. The wind produces waves by transferring energy to the water. The height depends on three things: wind speed, fetch (the distance of open water over which the wind blows) and duration (how long it has blown).

Wave Terms and Numbers

In deep water, wavelength in metres is about 1.56 times the period squared, and the speed in knots is about 3 times the period in seconds.

• Wave period 8 s: wavelength about 100 m, speed about 24 knots.
• Wave period 10 s: wavelength about 156 m, speed about 30 knots.
• Wave period 14 s: wavelength about 306 m, speed about 42 knots.

So a yacht making 8 knots in front of a 10-second sea is overtaken by each crest at about 22 knots relative speed, a useful fact when judging how long a wave takes to pass or break.

The biggest waves are bigger than the forecast. The significant wave height is the average of the highest third of waves. Individual waves vary, and the highest of roughly a thousand waves is nearly twice the significant height. A forecast of Hs 6 m therefore means that waves of 10 to 12 m can occur in a long gale. Freak waves are most likely where wind and current oppose each other, or where two wave systems cross.

What Makes Waves Dangerous

• Steepness: short-period waves of the same height are steeper than long ones and more likely to break.
• Wind against tide or current: a stream running against the wave direction shortens the waves and steepens them. The Agulhas Current off South Africa, where a south-west gale blows against the south-west-flowing current, is a famous example, as are the tidal races of the English Channel.
• Shoaling: waves begin to feel the bottom when the depth is less than half the wavelength, and break when the depth is about 1.3 times the wave height. The continental shelf edge (about 200 m depth) is particularly dangerous because ocean swell steepens as the depth reduces. In the Fastnet 1979 storm and the Bay of Biscay the shelf edge was a hazard.
• Cross seas: a change of wind direction from a passing front or a second system makes waves from two directions meet. The tops of the waves can interfere to form tall, pyramid-shaped waves with no pattern.
• Wave height compared with the yacht. A breaking crest whose height is comparable to the yacht's beam can roll her if it strikes beam-on. Heading the bow or stern into the sea greatly reduces the risk. This is why the tactics in this lesson all aim to keep the yacht end-on, or to cushion her with a slick or a drag device.

Storm Sails

When the third reef is not small enough, the boat needs dedicated storm sails. World Sailing's Offshore Special Regulations require them for offshore racing, and they are strongly recommended for any offshore cruising passage.

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The trysail

A trysail is a small, heavy, triangular sail set on its own track on the mast, separate from the mainsail's luff groove. It is sheeted to the quarters, not to the boom. The mainsail stays furled and lashed on the boom, and the boom is lowered onto the coachroof or into its gallows and secured, so it cannot swing. The advantages are that the trysail can be hoisted without first removing the mainsail, and that it does not rely on a boom which, in a severe sea, can be dangerous.

Its area is typically around 17.5% of mainsail luff times foot (P times E) under the ISAF/World Sailing offshore special regulations. It should be a high-visibility colour, so the boat is easier to see from the air or from a ship.

The storm jib

A storm jib is small (typically no more than 5% of the forestay height squared), heavy, cut flat, and ideally set on an inner forestay (a removable baby stay or cutter stay). Setting it inboard and further aft brings the centre of effort closer to the mast, improving balance, and keeps the crew working nearer the middle of the boat. A storm jib that relies on being hoisted around a furled genoa is not satisfactory: the furled genoa can unroll in a gale with catastrophic results.

Sheet leads

Storm jibs need sheet leads further inboard and forward than a genoa. Using the genoa car on the toe rail lets the leech twist open at the top, wasting drive and adding heeling force high up.

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Mark the correct sheet lead positions on deck in advance. Aim to balance the trysail and storm jib to give slight weather helm. Practise hoisting both on a calm day, with the crew who will be aboard, and time it. Many storm sails have never been out of their bags until the night they are needed.

Heaving-To

Heaving-to is the offshore "pause button". It stops the boat making progress, steadies her motion, and lets the crew rest, cook, navigate or carry out repairs.

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How to heave-to

1. Sailing close-hauled, tack without releasing the jib sheet, so the headsail is backed (sheeted to windward).
2. Ease the mainsail (or trysail) until it is just drawing or luffing slightly.
3. Put the helm down (tiller to leeward, or wheel turned to windward) and lash it.
4. The backed jib pushes the bow off the wind; the main and rudder try to bring it back up. The boat settles 40 to 60 degrees off the wind, making perhaps 1 to 2 knots of drift to leeward with very little forward way.
5. Adjust: if the boat tacks itself, ease the main more or lash the helm further; if it falls off and sails, harden the main or reduce headsail.

Why it works

As the boat drifts to leeward, the keel leaves a band of disturbed water, the slick, on her windward side. Waves crossing the slick tend not to break, which protects the boat. The boat rides with her shoulder to the seas, and the motion becomes dramatically easier.

Choosing the tack

Heave-to on the tack that takes you away from danger (lee shore, shipping lane) and, other things being equal, the tack that puts the bow most nearly into the dominant swell. In the Northern Hemisphere, as a depression passes and the wind veers, starboard tack keeps the bow heading into the veering wind and sea.

Limits

Long-keeled, heavy-displacement boats heave-to beautifully. Modern fin-keel, light-displacement boats with high freeboard may sail along at 3 knots instead of stopping, or fall beam-on; experiment on your own boat in moderate conditions. Heaving-to also needs sea room: drift rate of 1 to 2 knots over 12 hours can still be 20nm. As waves become very large and breaking, the slick may no longer protect the boat, and an active tactic is needed.

Lying Ahull

Lying ahull means taking down all sail, lashing the helm and leaving the boat to find her own position. Most yachts settle beam-on to the wind and sea.

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It is attractive because it requires no effort from an exhausted crew. But beam-on is the most dangerous position for a boat in breaking waves: a breaking crest only needs to be about the same height as the boat's beam to roll a typical yacht. In the 1979 Fastnet storm, boats lying ahull suffered a high proportion of knockdowns and capsizes.

Lying ahull is acceptable only in big but non-breaking seas, or as a brief pause. It should never be the planned tactic for a storm with breaking seas.

Running Off

Running before the wind and sea reduces the apparent wind, eases the motion and presents the boat's narrowest, most streamlined end to the seas. It is a good tactic when there is sea room to leeward and, preferably, when that is the way you want to go.

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The danger: too much speed

As seas build, the boat begins to surf. Going too fast down a wave, she can bury her bow in the back of the wave ahead, or slew sideways (broach), ending up beam-on in the breaking crest, which is the knockdown position. In extreme seas she can be thrown end over end (pitchpoled).

Controlling speed

1. Reduce sail progressively: small headsail only, then storm jib, then bare poles.
2. Steer to take the seas about 15 to 20 degrees on the quarter rather than dead astern, which reduces the tendency to surf straight down the face and broach. Active, skilled helming is essential.
3. If still too fast under bare poles, tow warps in a bight astern (traditional) or, much better, deploy a drogue.

The target speed depends on the boat, but a common aim is to keep boat speed well below the speed of the waves so they pass under the boat, without slowing so much that steerage is lost.

Steering and crew

Running off by hand in a big sea is exhausting and demands experience. Helmsmen typically need relieving every 30 to 60 minutes. The helmsman should look astern regularly to see big crests coming. If the crew cannot maintain good helming, a drogue lets the boat look after herself.

Drag Devices

Drogues (from the stern)

A drogue is towed astern to slow the boat while running off and to hold the stern to the seas. It is not intended to stop the boat.

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Single-element drogues (a cone or a Galerider-type device) work well, but in steep seas the drogue can be pulled through a wave face or out of the water, so the boat surges forward and then the line snatches tight, imposing huge loads. Long rodes help: the drogue should sit two or more wavelengths astern and well below the surface.

The series drogue

The series drogue, developed by Don Jordan after studying capsizes, consists of a long rode with 100 or more small fabric cones along it, ending in a weight (often a length of chain) to keep it sunk.

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Because the cones are spread over a long length, some are always in solid water, and the load is applied smoothly rather than in shocks. It slows the boat to around 1 to 3 knots and holds the stern firmly to the seas. Tests and experience suggest it is very effective at preventing broaching and pitchpoling. It is attached to a bridle on strong points on both quarters.

Drawbacks: the boat takes breaking seas on the stern, so the companionway must be closed with strong washboards and the cockpit must drain quickly; and recovery is slow and laborious, typically hauled in using a winch, cone by cone.

Sea anchors (from the bow)

A sea anchor is a large parachute (typically 2.5 to 4.5m diameter for a yacht) deployed from the bow on a long nylon rode, often 10 or more times the boat's length. It holds the bow into the wind and sea, almost stopping the boat: drift is reduced to under a knot.

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Deployment:

1. Rig a strong bridle to the bow or a chafe-protected rode through the bow roller. Chafe is the main cause of sea anchor failure.
2. Lower the sail; motor or drift slowly so the boat is heading downwind of the deployment point.
3. Deploy over the windward side from the cockpit, paying out the rode under control, keeping it clear of the keel, rudder and propeller.
4. Let the rode stretch out until the parachute fills and the bow comes round.
5. Rig a float and trip line to the parachute apex so it can be collapsed for recovery.

Multihulls generally use sea anchors because they lie well to them. Many monohulls tend to "sail" around on the rode and yaw, and the rudder can be damaged by the boat being pushed backwards by breaking crests. Some monohull skippers combine a small sea anchor off the bow quarter with a heaved-to sail plan.

Choosing between them

Knockdown and Capsize

A knockdown is when the boat is laid over so the mast reaches or passes horizontal. A capsize (inversion) goes beyond that; a 360 degree roll means the boat has gone completely over.

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Immediate actions

1. Hold on. Crew in the cockpit should already be clipped on with short tethers.
2. As the boat comes back up, head count: everyone accounted for? Anyone in the water? Initiate MOB procedures immediately if so.
3. Crew move their weight to the high side to help her come up; the helm steers to bring the bow towards the wind and spill power from any sail.
4. Check for injuries.
5. Check for water ingress: pump, find any broken windows or hatches, and fit storm boards.
6. Check the rig: if the mast is down, clear it quickly before it holes the hull, using bolt-cutters and a hacksaw.
7. Reconsider the tactic: whatever you were doing was not working. Change to a different approach.

A modern ballasted keel yacht usually has an angle of vanishing stability around 115 to 130 degrees, so she will normally right herself from a knockdown. But a breaking wave of sufficient size striking a beam-on boat can overcome static stability, which is why active tactics that keep the boat end-on to the seas are preferred.

Stability and Design Categories

How well a yacht recovers from a knockdown depends on her stability curve. The righting lever (GZ) is the horizontal distance between the centre of gravity and the centre of buoyancy, and it creates the force that rights the boat. It increases with heel, reaches a maximum around 50 to 70 degrees, then decreases to zero at the angle of vanishing stability (AVS). Beyond that angle the boat is stable upside down. A typical cruising monohull has an AVS of 115 to 130 degrees, but wide beam, high freeboard and a tall coachroof can lower it. Water in the cockpit and a heavy rig aloft lower the stability again.

The category is on the builder's plate. A category B boat can be taken offshore, but the crew should know that a gale beyond Force 8 may exceed the design assumptions. The Stability Index (STIX) is a number that combines length, beam, displacement, downflooding angle, and the AVS, and which the designer uses to classify the boat. Most cruising yachts get a STIX well above the threshold for their category.

Practical points:

• Keep heavy gear low: batteries, water tanks, chain.
• Do not carry heavy items on deck or in the rig.
• Keep the downflooding angle (where water enters through an open hatch or vent) high by keeping hatches and vents closed.
• A boat that has been knocked down once may do so again: reduce risk by moving to a different tactic.

Navigation, Communications and Damage Control

Navigation

• Plot a position at least hourly, even when conditions are bad. In a gale you cannot be sure the electronics will survive, so keep a dead reckoning plot (course, speed, time) on paper.
• Allow for increased leeway, which can be 10 to 15 degrees when heaved-to or under storm sails.
• Mark on the chart the bailout options: the nearest safe harbour in each wind direction, with its approach conditions, and the position of shoals and shelf edges to avoid.
• Keep a record of the barometer every 30 minutes. A rapid rise and a wind veer after a cold front indicate the worst may be passing, but a secondary low can follow.

Communications

• Keep the VHF, DSC and handheld on charge. Call a PAN PAN early if you are damaged or unable to handle the conditions. A MAYDAY is for grave and imminent danger.
• Report your position and plan to the Coastguard or a nominated shore contact every few hours.
• Use satellite or SSB weather updates to judge how long the storm will last.

Damage Control

• Hull: check bilges at regular intervals. If water ingress is found, follow the procedures in the fire, flooding and abandon ship lesson.
• Rig: inspect shrouds, rigging screws, mast step and spreaders each time you tack or after a knockdown. Carry bolt croppers to clear a dismasted rig quickly.
• Steering: rehearse the emergency tiller. If the rudder is damaged, steer with a drogue or sails.
• Engine: rough weather stirs up sediment in the fuel. Bleed the engine and carry spare filters. Starting problems can occur when the engine is heeled, so keep the battery charged.

Crew Management in a Gale

Many heavy weather incidents are caused by fatigue, cold, hunger and seasickness. The skipper manages these as carefully as sails.

• Watch system: shorten watches to 2 hours on deck in the worst conditions. Keep one experienced helmsman always on deck, with a second person as lookout in the shelter of the sprayhood.
• Food and drink: hot, high-calorie food in flasks and bowls with a wide base. Drink regularly; dehydration affects decision-making as much as lack of sleep.
• Seasickness: treat it early and make sure those who are sick are clipped on and given easy jobs. Seasick crew can be hypothermic before they notice.
• Cold: layers, waterproofs and a hat, plus a dry change of clothes below. Hypothermia is insidious.
• Skipper's role: a skipper who is exhausted makes poor decisions. Delegate the helm, rest in turns, and announce decisions clearly. Use the log to record reasoning.
• Morale: explain the plan, the time that the front is expected to pass, and the safe options. People bear difficulty better when they know what to expect.

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Image: [Arrivisto](https://commons.wikimedia.org/wiki/File:ParaAnchor_01.jpg), [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0), via [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:ParaAnchor_01.jpg)

The photograph shows a typical parachute sea anchor packed in its deployment bag. Keep it somewhere accessible, with the rode flaked ready to run, and practise the drill before you need it.

Learning from Disasters: Fastnet 1979

In August 1979, a fast-deepening depression swept across the Fastnet Race fleet in the Western Approaches with winds of Force 10 and steep breaking seas. Fifteen sailors died, 5 yachts sank, and over 100 were knocked down. The RYA/RORC inquiry produced lessons that still shape heavy weather practice.

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Image: NOAA SMS-2 imagery annotated by ViridLeWiki, public domain, via [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:1979_Fastnet_Race_Storm_1979-08-13_0900Z.png). Downscaled and converted to JPEG.

The satellite image shows the small, intense depression approaching the British Isles on the morning of the storm. Forecasts at the time failed to predict how fast it would deepen, which is why a skipper always plans for the worst plausible conditions, not the forecast average.

Key lessons:

• Wave steepness, not wind speed, was the killer. The storm crossed relatively shallow water over the continental shelf and the seas became steep and breaking.
• Actively managed boats fared better. Boats that were steered actively or towed warps or drogues suffered fewer knockdowns than those left lying ahull.
• Stay with the boat. Several deaths were connected with abandoning to liferafts; many of the yachts abandoned were later found afloat. Step up into a liferaft only when the boat is sinking under you.
• Equipment matters. Harness and tether failures, washboards lost in knockdowns, and poor stability in some light-displacement designs led to changes in equipment standards and stability requirements.

The 1998 Sydney Hobart storm, which killed six sailors, reinforced the same message about steep seas, stability and the dangers of premature abandonment.

Choosing a Tactic

There is no single correct tactic. The decision depends on:

1. Sea state: breaking or not, wave period and steepness.
2. Sea room: how far to the nearest danger downwind.
3. The boat: hull form, keel, rudder, displacement, stability.
4. The crew: experience, number, fatigue, seasickness.
5. Gear: storm sails, drogue, sea anchor available and practised.

A typical progression for a monohull:

Worked Example: Running Off with a Lee Shore Ahead

Conditions: sustained 45 knots, 6m confused seas. You have been running off under bare poles for 6 hours, hand-steering. Speed is rising to 9 knots on each wave and the boat has nearly broached twice. The crew is tired. A lee shore is 20nm downwind. A series drogue is aboard and rigged in its bag on the stern; a parachute sea anchor is also aboard.

Assessment. At 6 to 7 knots average, 20nm is about 3 hours. Speed is too high; broaching risk is increasing as the helmsmen tire. Running off cannot continue for long with the lee shore ahead.

Decision. Deploy the series drogue now. It will slow the boat to around 2 knots, giving about 10 hours of drift before reaching the lee shore instead of 3, buying time for the gale to ease or the wind to shift, and make the boat largely self-steering, so the crew can rest. The sea anchor would reduce drift further but deploying a parachute from the bow in 6m confused seas, from a boat running off, is more hazardous.

Execution.

1. Brief the crew: who handles the bridle, who pays out, who steers, and everyone clipped on.
2. Attach the bridle to both quarter strong points; check chafe protection.
3. Steer to keep the stern to the seas while the weighted end is lowered and the rode paid out under control, keeping hands and feet clear of the line.
4. Once loaded, centre and lash the helm.
5. Close the companionway fully with washboards; all crew below except a lookout in the companionway or a watch on a short tether.
6. Monitor chafe at the bridle every hour; log position and drift.
7. Start a rest rotation.

Worked Example: Choosing a Tactic as a Depression Passes

You are 120 nm south-west of Ireland in a 12 m cruising yacht, a category B design with four crew, one of whom is seasick. A deepening depression is forecast to pass to the north, giving SW Force 9 gusting 10 for around 8 hours, then a veer to NW Force 8, with waves up to 8 m. The barometer has fallen 9 hPa in 3 hours. The nearest lee shore (the Irish coast) is 150 nm to the north-east.

Assessment.

1. Sea room is ample: running off at 3 knots for 14 hours is only 42 nm. A lee shore is not an immediate danger.
2. Conditions are above the yacht's comfortable limit but within her design range. The crew is tired.
3. After the cold front a veer to NW will create a cross sea: the SW swell will persist while the new NW wind sea builds.

Decision. Rig the trysail and storm jib before the wind arrives, and heave-to on the tack that best lies to the new wind direction after the front (starboard tack in the Northern Hemisphere, as the wind veers). As the seas become steep and breaking, deploy a series drogue and run off at 1 to 2 knots if the yacht lies badly. Keep one helmsman on deck with a lookout, close the washboards, check every hour and record pressure and wind in the log.

Outcome check. After the front passes, the wind veers to NW and the seas become confused. The crew reassess: if the yacht is lying well, remain heaved-to; if broaching begins, change to a drogue. Review every two hours and keep the next decision in mind.

Worked Example: Wave Speed and Running Off

You are running off in a 10-second period swell at 8 knots with 5 m waves. Each wave has a speed of about 30 knots (3 times 10), a length of about 156 m. The yacht's speed is therefore 22 knots slower than the crests, so each crest passes you at a relative speed of about 22 knots (11.3 m/s). In still terms, a crest 156 m behind you reaches you in about 14 seconds.

When the helmsman picks up speed to 12 knots on a wave face, the relative speed drops, the yacht begins to surf and the bow may bury in the trough ahead. Target speeds of 5 to 7 knots, under storm jib or bare poles with a drogue, keep the yacht in control. Check for a rising speed on the log: if it exceeds 8 to 9 knots on each wave, slow the boat before the helmsman loses control.

Common Mistakes

• Waiting to prepare. Prepare and reef early; everything is harder once it is blowing.
• Storm sails never practised. Hoist them in calm conditions and mark the sheet leads.
• Lying ahull in breaking seas. Beam-on is the most vulnerable position.
• Running too fast. Control speed with sail area, warps or drogue before the boat starts surfing and broaching.
• Short drogue rode. It must reach two or more wavelengths astern.
• Chafe on bridles and rodes. Protect at every fairlead and check hourly.
• Storm jib on genoa car. Use inboard leads to prevent twist.
• Leaving the companionway open while running before breaking seas. One wave down the hatch can flood the boat.
• Abandoning to the liferaft too early. The yacht is the best liferaft until she is actually sinking.

Summary

• Heavy weather is defined by the boat, the crew and above all breaking seas.
• Prepare early: below decks, on deck, aloft and crew. Reef early.
• Trysail on its own track and storm jib on an inner forestay, with inboard sheet leads, practised before needed.
• Heave-to to rest and wait; it works best on traditional hulls and needs sea room.
• Lying ahull exposes the beam to breaking seas: avoid it in breaking conditions.
• Running off needs sea room and speed control; drogues, especially series drogues, prevent broaching.
• Sea anchors from the bow nearly stop the boat; they suit multihulls and situations with little sea room.
• After a knockdown: head count, injuries, water, rig, then change tactic.
• Fastnet 1979: active tactics and staying with the boat save lives.

Check Your Understanding

1. Why is the sea state, rather than the wind speed, the main factor in heavy weather danger?

Answer: Boats are knocked down and capsized by breaking waves striking them, especially beam-on. A boat can cope with very strong winds in flat water; it is steep, breaking seas that overwhelm her.

2. List five below-decks preparations for heavy weather.

Answer: Any five of: stow and secure all loose items; secure floorboards, batteries and heavy items; rig lee cloths; pump bilges and check pumps; close hatches, portlights and unneeded seacocks; fit washboards with lanyards; prepare hot food and drinks in flasks; position grab bag, VHF and EPIRB; fix position and update the log.

3. Why is a trysail set on its own track rather than in the mainsail groove?

Answer: So it can be hoisted without first removing the mainsail, which stays furled and lashed on the secured boom. It also does not depend on the boom.

4. Describe how to heave-to and how the boat stays in position.

Answer: Tack without releasing the headsail so it is backed, ease the main, and lash the helm to leeward. The backed headsail pushes the bow off; the main and rudder bring it back up. The boat lies 40 to 60 degrees off the wind drifting slowly to leeward, leaving a protective slick to windward.

5. Why is lying ahull dangerous in breaking seas?

Answer: The boat lies beam-on, presenting her greatest area to breaking crests. A breaking wave about as high as her beam can roll her.

6. What is the difference between a drogue and a sea anchor?

Answer: A drogue is towed from the stern to slow a boat running off and keep her stern to the seas; she keeps moving at 1 to 3 knots. A sea anchor is a large parachute deployed from the bow to hold the bow into the wind and sea and nearly stop the boat.

7. Why does a series drogue avoid the snatch loading of a single-element drogue?

Answer: Its many small cones are spread over a long rode, so some are always in solid water even when part of the rode is pulled through a wave, giving continuous, smooth braking.

8. After a knockdown, list your first actions in order.

Answer: Hold on; head count and MOB check; crew weight to the high side and steer the bow towards the wind; check injuries; check for water ingress and pump; check the rig and clear it if down; then change tactic.

9. Name three lessons from the 1979 Fastnet storm.

Answer: Steep breaking seas rather than wind speed caused the losses; actively managed boats did better than those lying ahull; and abandoning to the liferaft too early cost lives, as many abandoned yachts survived. Equipment failures (tethers, washboards) and stability also led to new standards.

10. You have 8nm of sea room downwind in a severe gale with breaking seas. Would you run off with a drogue? Why or why not?

Answer: Probably not. Even at 2 knots, 8nm is only 4 hours of drift. With limited sea room, a sea anchor or heaving-to under minimal sail (or clawing off under storm sails if possible) is preferable, since these minimise drift.

11. A forecast gives a significant wave height of 5 m. What size of individual waves should you expect, and why does it matter?

Answer: The significant wave height is the average of the highest third of waves. The highest waves in a long gale can be nearly twice that, so waves of about 9 to 10 m can occur. Tactics, sea room and equipment must allow for the biggest waves, not the average.

12. Calculate the speed and length of a wave with a 12-second period in deep water. What does this tell you about a yacht running at 7 knots?

Answer: Speed is about 3 times the period, so about 36 knots. Wavelength is about 1.56 times the period squared, about 225 m. The wave overtakes the yacht at about 29 knots relative speed, so the yacht cannot outrun it and must be controlled by sail area, helming and drag devices.