May 2

Written by:
5/2/2011 5:01 AM 

Tahiti is 2400 nautical miles from New Zealand across one of the most difficult patches of water one can enter.  Easterly trades dominate the Pacific Ocean between 10° - 35°S Latitude.  To make proper easting one must go further South to found the westerly winds of the Roaring Forties.  Unlike the warmer  winds to the North the Southern Ocean’s westerly winds are fierce and cold.  Gales with 40+ knot easterly winds are common and one cannot do much but heave to or forereach until favorable winds return. 

My mind is not yet made up, but I know I blew through much of the South Pacific and I’d hate to move into the Indian Ocean before I’ve done all that I wish in this great bowl of blue.    To return will be no small test and in preparation I’ve been reading about the differences between two common storm tactics.  I thought I’d share that info here.  In the mean time Jargo and I are both getting stronger.  I hope she can splash back into the Whangarei River in 7 – 10 days.  Tomorrow I am going to finish her sanding and fare the bottom for paint.

 

©2005 Beth A. Leonard

HEAVING TO AND FOREREACHING:

Mastering these key boathandling techniques makes sailing safer – and more fun

by

Beth A. Leonard

The 39-foot, Bob Perry-designed cutter, Isalei-Rua, bounded over the white-crested waves in

King George Sound, the large outer harbor of the small city of Albany on the southwest corner of

Australia. With a single reef in the main and the motor, she was making good between 4 and 5

knots close-hauled into 25 knots of breeze. I found the hum of the wind in the rigging and the

occasional rush of water down the decks exhilarating, but I didn’t think her owners felt the same.

Bob’s hands looked relaxed enough on the wheel, but he wasn’t smiling. The muscles in

Jacquie’s jaw were tight, and her hand was white-knuckled on the binnacle.

After several years of preparation, Bob and Jacquie Donovan had just embarked on the cruising

life. My partner, Evans Starzinger, and I had been talking with them about storm tactics a few

days before, and they said they’d like to learn how to heave to on Isalei-Rua. Now we had

enough wind to give it a try, so we were heading out into open water to see how the boat behaved.

With her cutaway forefoot, modified fin keel and skeg hung rudder, we expected she would

respond like Perry’s Valiant design and heave to quite easily.

 

FOREREACHING VERSUS HEAVING TO

Five miles out from the harbor entrance, Evans leaned forward and said something to Bob. Bob

throttled back and cut the engine. Under the reefed mainsail, the boat slowed gradually. Bob

kept the helm centered, and after a few minutes Isalei-Rua ended up at a 45 degree angle to the

wind, moving forward at between one and two knots. She would slowly come up to the wind

until the mainsail stalled and started to luff, bringing her almost to a halt. She’d fall off ten or

fifteen degrees and start sailing again, building up speed until she got to two knots. Then she

would work back up into the wind until the mainsail stalled. And so she went at a slow jog across

the water, weaving back and forth.

As she bled off speed, waves stopped washing down the decks, and spray stopped flying over the

coachroof. Everything got quieter and calmer, and the motion became easy and slow, like a

rocking horse. Jacquie’s grip relaxed on the binnacle, and Bob smiled. “This is forereaching,”

Evans said. “You’re jogging along to windward, not making much forward progress, but not

going sideways either. You can see you still have a small wake behind the boat. Now let’s try

heaving to.”

We raised their staysail, which completely filled the inner foretriangle. With the additional sail

sheeted in, Isalei-Rua dropped her shoulder and took off like a freight train, driving through the

waves and then crashing down with a shudder. “Okay,” I said. “Turn her through the wind but

don’t release the staysail sheet.” Bob spun the wheel and Isalei-Rua checked and started to come

up into the wind. The tightly sheeted main luffed and then filled on the other side. The staysail

tried to follow, but the sheet restrained it. The headsail shivered and then backed as Bob centered

the wheel. Isalei-Rua coasted to a slow stop, her head about 45 degrees off the wind, her angle of

heel reduced from more than 30 degrees to about 15. Evans played with the helm, eventually

locking it off about a quarter of a turn to windward. Though the boat still took the seas on her

starboard bow, the GPS showed us slipping through the water at almost a ninety-degree angle to

the wind.

All of the noises that accompany a boat making her way to windward in a stiff breeze died away,

and Isalei-Rua sat like a contented seagull gently riding the waves. As when we were

forereaching, the boat jogged up until the mainsail stalled and then fell off. But the backed jib

prevented her from getting any forward momentum, and the motion was only noticeable when I

concentrated on it. The wind carved spume-flecked furrows in the wave tops, but these ended

along with the waves at a patch of smooth water extending about ten feet out from the windward

side of the boat. I pointed this out to Bob and Jacquie. “That’s the slick. See, it’s sort of a

wake, created by the drift of the boat to leeward. That’s how you know you’re really hove to.”

 

THE MECHANICS OF HEAVING TO AND FOREREACHING

An indispensable storm tactic, heaving to can be viewed as the equivalent of pulling on a

handbrake in a car. It slows everything down and allows crews to enjoy a lovely picnic lunch on

a summer afternoon a few miles from shore, make a repair to a sail while on passage, or take a

time-out to look over an unfamiliar harbor entrance or talk over a boat handling decision.

Forereaching can be considered a variation on the theme for boats with modern underbodies.

Most boats forereach quite comfortably under just a mainsail, so it’s easiest to start with this

tactic when experimenting with your own boat. Generally speaking, you can forereach on one

less reef than you would use for sailing in the given conditions. To forereach, the main should be

sheeted to the centerline and the helm locked in position to hold the boat close-hauled. Start by

locking the helm amidships and see what happens. If the boat falls off to a broad angle and just

keeps sailing, you need to turn the helm more to windward. If it gets in irons or tacks through,

you need to turn the helm a bit to leeward. You’re forereaching when the boat jogs up to

windward, the sail starts to stall, and the boat falls off to leeward and starts sailing again. In

addition to slowing things down, forereaching is a perfectly acceptable storm tactic so long as the

waves are not breaking. We have forereached under a deeply reefed main on our 47-foot

aluminum sloop, Hawk, into very large but well-spaced and not breaking seas for thirty-six hours

in winds gusting over 50 knots in the Southern Ocean. But the few times we have been in

breaking seas, we have always switched to another tactic (see sidebar, “Breaking waves”).

Heaving-to means setting up the sails and the rudder so that they oppose one another and the boat

stops making headway. In the textbook case, the boat will ride with the wind and waves forty to

sixty degrees off her bow and slide slowly to leeward creating a slick that causes waves to break

before they reach the boat. As with forereaching, boats tend to jog up to windward, fall off, and

then jog up again, making little headway and a fair amount of leeway. Exactly how much time

the boat spends making headway versus leeway depends upon the hull configuration, the rig, the

center of effort, and the size and shape of the waves, among other factors. A traditional full-

keeled boat will normally make a knot of leeway and almost no headway; modified fin-keel boats

with skeg hung rudders may make up to two knots of leeway. Most fin-keeled boats will

continue to make headway, and are thus not technically hove to. Instead, they will forereach,

making a knot or two of headway and less than a knot of leeway.

Different boats require different sail combinations and rudder angles to achieve a hove-to

position, and the same boat will require different amounts of sail and rudder angle to heave to in

different wind speeds and wave conditions. In gale force winds, many heavy displacement

cutters and sloops with traditional underbodies will heave to under a single- or double-reefed

main sheeted in to the centerline, a backed headsail sized to between two-thirds and three-

quarters of the foretriangle, and the helm lashed within a quarter turn of the centerline. In storm

force winds, many traditional boats will heave to under just a storm trysail with no headsail at all.

Our first boat, the Shannon 37 ketch, Silk, had a centerboard in a modified fin keel and a skeg-

hung rudder. Like most ketches with full-sized mizzens and traditional underbodies, she hove-to

on the mizzen alone without a backed headsail. We used the full mizzen in gale force winds, and

put in a reef at around 40 knots depending upon the wave state. With the helm locked on the

centerline, we would adjust the mizzen sheet so the boat sat 45 to 50 degrees to the wind. We

then fixed the mizzen boom in position with a vang from the end of the boom to a stanchion base.

Silk would drift at about a knot and a half dead downwind. Yawls and ketches with small mizzen

sails lack the sail area aft to keep them up into the wind in all but the most extreme conditions.

They heave to best if treated like cutters or sloops.

To experiment with heaving to on your own boat, go out on a breezy day with at least 25 knots of

wind. Reef the main so the boat is comfortable in the conditions, and then size the jib to between

80 and 100 percent of the foretriangle. Turn the boat through the wind, but do not release the jib

sheet. Lock the rudder in a position that holds the boat’s head 40-60 degrees off the apparent

wind. Adjust the size of the sails if necessary: too little sail overall will prevent you from getting

the boat’s head up even with the helm hard to windward; too much headsail will cause the boat to

fall off beam to the wind in any lulls; too much mainsail will bring the boat too close to the wind

or even allow it to tack through in any gusts.

When the boat has bled off speed, use a GPS to determine the actual direction of drift, and check

the boat’s wake to see if you are making any headway or just leeway. Adjust the sails and rudder

again, and see if you can stop all forward motion and make only leeway. If you can do that, you

will be properly hove to, and if the wind is strong enough you should be able to see the slick to

windward. Many experienced open-ocean sailors believe the slick protects the boat in extreme

conditions with large breaking waves or cross-seas by forcing the seas to break before they reach

the boat.

On a fin-keel racing boat with a spade rudder, you may only be able to slow the boat down so that

you are forereaching at a couple of knots. Full-keeled, heavy displacement boats stall out forty

degrees to the wind, giving them an 80-degree window within which they’ll make no headway.

But Hawk, with her fin-keel and spade rudder, will still have some forward momentum as close as

20 degrees to the apparent wind, so the window within which we can heave to is much smaller.

A slight change in wind angle or a wave that knocks her bow off will have Hawk sailing again.

Friends of ours on racier cruising boats have had the same experience. If they manage to get the

boat to stop, the situation is not stable and has to be monitored constantly.

The leeway a boat makes while hove-to means that you do need sea room – a couple hundred feet

if you’re just stopping for a few minutes to take stock, a couple of miles if you’re enjoying lunch

with a few bottles of wine. Offshore in gale conditions you need a lot more room – most boats

will drift between twenty and fifty miles to leeward every twenty-four hours.

If your headsail sheets outside of your stays, or if you have a staysail stay, the sheet or the sail

will likely be chafing on something. While this is no problem for an hour or so, if you may heave

to at sea for long periods of time you will need to experiment with ways to eliminate the chafe.

The easiest solution is to use a staysail or storm jib sized to sheet inside the lifelines and shrouds.

Other solutions include rigging a short sheet that runs inboard from the clew to the sheet winches

or using a snatch block to hold the sheet off the lifeline or shrouds.

Because most boats will forereach under just a reefed mainsail without a headsail, chafe is not

normally a problem with this tactic. Also, when forereaching you don’t need to worry nearly as

much about leeway as when heaving to. Forereaching allows you to continue to make slow miles

toward your destination without beating up the boat or yourself. But forereaching does not

reduce the boat’s motion as much as heaving to, and in extreme conditions the boat will not be

protected by a slick as it will if the boat can be properly hove-to making only leeway. If you’re

in extreme conditions, trying to stop the boat completely, or need a stable platform to make a

meal or fix something on deck, heaving to will be a better tactic. But if you’re just trying to slow

the boat down and can’t afford to make any leeway, forereaching makes more sense.

 

FINE-TUNING

Isalei-Rua lay quietly in the wind, drifting slowly to leeward. But Evans wasn’t satisfied. “That

sheet lead’s a problem,” he said, pointing to the staysail sheet. The staysail was large enough that

it could not be sheeted inboard of the stays and lifelines, so when the sail was backed the sheet

ran across both. “It wouldn’t matter for an hour or so, but it will chafe through it you heave to

overnight. Let’s try your storm jib.”

Bob dropped down below and returned with a small sail bag. I turned to Jacquie and said, “Let’s

drop the staysail and put up the storm jib.” She hesitated, afraid to leave the cockpit. Then she

shrugged and joined me. Bob handed me the storm jib and we worked our way up to the

sidedeck. Despite the wind whipping the four-foot waves into a froth, the motion was gentle, and

the decks were dry. Moving around the boat took almost no effort.

Jacquie released the halyard at the mast while I crouched behind the staysail stay. The backed

sail fell in a neat pile at the bottom of the stay, and I had no problem flaking it neatly despite the

strong wind. “We often heave to just to do a headsail change,” I told her. “It keeps the foredeck

person dry and makes it much less likely someone will go overboard.” She helped me roll the

sail into a bundle and get it back in its bag, then I hanked on the storm jib. Evans and Bob had re-

led the sheets inboard of the stays, and we tied them to the clew. Then we raised the sail, and

once it was up Evans sheeted the windward sheet in until it was backed just as the staysail had

been. The sheet led cleanly without chafing on anything. “This is the sail you’d really want to

use if you were heaving to in a storm at sea,” Evans said. “In stronger winds you’d probably

need to take another reef in the main to balance out the sail plan.”

As we turned back toward the harbor entrance, Jacquie and I dropped the storm jib and Evans

eased the main. Soon we were flying from wave to wave, the bright sunshine finally warming us

as the apparent wind speed dropped. It would take a lot more practice in a variety of conditions

before Bob and Jacquie would know instinctively how to heave to on Isalei-Rua. But I could tell

that they had gained a good deal of confidence in the boat and themselves in one short outing.

© 2005 Beth A. Leonard

 

 

Sidebar to “Heaving to and Forereaching”:

BREAKING WAVES

Waves, not wind, do most of the damage to boats during storms at sea. But there is a big

difference between normal ocean waves, even very large ones, and what are called “breaking

waves.” Waves with whitecaps or with cresting foam and whitewater on top are not breaking

waves and do not generally constitute a danger to a well-found boat. Breaking waves normally

develop only when something opposes the movement of the wind driven waves. A strong ocean

current like the Gulf Stream or the Agulhas current running counter to the prevailing waves or

shoaling water along the edge of a continental shelf can cause storm-driven waves to rise up like

combers running onto a beach. As they get higher and steeper, the crest of the wave becomes

unstable and begins to collapse down its face, just as happens with a surfing wave. People who

have experienced them have compared the wave faces to huge, moving waterfalls and described

the breaking waves as rolling, tumbling avalanches of water.

To get some idea of the magnitude of the forces in a breaking wave, consider that every cubic

yard of water weighs more than one ton. A breaking wave may contain several hundred tons of

water moving at speeds of up to 30 knots. In the collapsing front of the wave, those forces will be

twisting and turning. Most classic stories of boats being pitchpoled or rolled, like when the

Smeetons got pitchpoled in Tzu Hang on their first attempt to round Cape Horn, are generally

attributed to breaking waves.

Breaking waves are mercifully rare. They are unmistakable when experienced and cannot easily

be confused with large, regular, cresting seas. We have been in breaking waves only twice in our

75,000 nautical miles and both were avoidable. Experts disagree on what tactics will best protect

the boat in these conditions. In both cases, we ran off towing a drogue. Some very experienced

sailors argue that the slick created by heaving to will cause the waves to break before they reach

the boat. While we might consider heaving to in a boat that did so well, we would never choose

to forereach into breaking waves.