Presented at 32nd Annual Seven Seas Cruising Association Convention in
Melbourne, Florida November 10, 2007
STORM MANAGEMENT FOR CRUISERS
What do you do when you are sailing offshore and you find
yourself in a storm? How can you deal with storms so you don't break
expensive gear and people don't get hurt?
Storm management for cruisers is mostly common sense and is within the
ability of ordinary people who venture offshore in seaworthy yachts.
Storm management is all about energy management. Large storms have
lots of energy, and you need to learn how to deal safely with all that
energy if you want to stay out of harms way. Storm management is
actually energy management. If the energy in a storm gets transferred
to your yacht - coupled to your sailboat - then you have to safely dissipate
all that energy so that nothing bad happens.
Most people don't understand the physics of storms and how they
couple energy to your yacht. The basic concept is this: A
storm contains massive amounts of energy, but if you don't let that energy
climb on board your yacht, you will fare well during a storm.
Conversely, if you sail in an uncontrolled and dangerous manner allowing the
storm to couple its destructive energy to your yacht, then don't be
surprised if you or your yacht are hurt.
First, let's talk about energy in a simple way so you can understand the
magnitude of the forces at work in a storm. What you need to
understand is the amount of energy in your yacht. I will give you a
simple scale of relative energy that is easy to understand.
To create this energy scale, you need some simple mathematics to comprehend
Here is a formula that puts things in perspective:
KE = 1/2 Mass x Velocity Squared
This equation states that the kinetic energy of your yacht is equal to one
half the mass of your yacht multiplied by the square of your yacht's speed.
When you look at this equation, you can pretty much ignore the mass of your
vessel because it isn't going to change significantly during a storm unless
you throw things overboard and lighten ship.
If you ignore the mass of your boat, the equation becomes KE = Velocity
Squared. This simplified equation works well for purposes of our discussion.
The equation means that the amount of
energy your boat has to safely dissipate is directly related to the square
of the speed of your yacht. If you double the speed, the kinetic
energy goes up four times.
Check out these numbers to see how the relative kinetic energy of your vessel
changes with your speed.
YACHT SPEED = 0 KINETIC ENERGY = 0
YACHT SPEED = 1 KINETIC ENERGY = 1
YACHT SPEED = 2 KINETIC ENERGY = 4
YACHT SPEED = 3 KINETIC ENERGY = 9
YACHT SPEED = 4 KINETIC ENERGY = 16
YACHT SPEED = 5 KINETIC ENERGY = 25
YACHT SPEED = 6 KINETIC ENERGY = 36
YACHT SPEED = 7 KINETIC ENERGY = 49
YACHT SPEED = 8 KINETIC ENERGY = 64
YACHT SPEED = 9 KINETIC ENERGY = 81
YACHT SPEED =10 KINETIC ENERGY = 100
YACHT SPEED =12 KINETIC ENERGY = 144
YACHT SPEED =16 KINETIC ENERGY = 256
YACHT SPEED =20 KINETIC ENERGY = 400
This scale that shows the relative amount of kinetic energy
you have on board at different speeds. You can see that when your
yacht speed is zero, you have essentially zero kinetic energy. At one knot, you have one unit of kinetic energy, at four
knots you have 16 units of kinetic energy, at eight knots you have 64
units of kinetic energy, and at 16 knots of boat speed you have 256 units of
kinetic energy on board.
When my sailboat was surfing at eighteen knots in the Atlantic Ocean during
a storm, I had to safely dissipate 324 units of kinetic energy to stay out
of trouble. My catamaran was going so fast and had so much energy on
board that the slightest mistake by the helmsman or autopilot could result
in personal injury, damage to the yacht, broach, or even capsize.
When your speed gets out of control, the kinetic energy
rises astronomically, and you better not make a mistake, because all
that energy is going to hurt you.
This relative scale of kinetic energy shows that when you
are hove to or lying to a parachute during a storm, the kinetic energy of
your yacht is close to zero. When you are running downwind trailing a
drogue at a few knots in a controlled manner, your kinetic energy remains at
safe levels. But when you are sailing along at eight knots and surfing
down the faces of waves at eighteen knots, you are courting disaster because
if you lose control of all that energy and dissipate it in an unsafe manner,
bad things are going to happen to you and your yacht.
STORM MANAGEMENT IS ALL ABOUT ENERGY MANAGEMENT
1. Uncontrolled energy is what destroys yachts
during a storm. Yachts get going too fast, and then lose control
and broach. Yachts with high levels of kinetic energy jump off the
crests of waves into the troughs and the uncontrolled energy breaks
bulkheads loose and destroys rigs. Yachts with high levels of energy
sail into walls of water (called waves) and their yacht shudders from stem
to stern as they crash into the seas.
2. Yachts that safely dissipate their kinetic energy survive storms
without damage. You must monitor and control the energy in your
yacht so that it never reaches dangerous levels.
3. If you are not careful, stormy seas and strong winds will
transfer their energy to your yacht, and when that energy reaches dangerous
levels, bad things will happen. Rudders break off, yachts roll and
pitchpole, masts come down, and people sustain injuries.
YOUR JOB IN A STORM
1. Position your yacht in a location so that
it's exposed to the least amount of energy. Storm avoidance or at
least positioning yourself in the "safe" semicircle will do a lot to
limit the amount of energy that you have to deal with in a storm.
2. Once you find yourself in a storm, you must decouple the energy
of the storm from your yacht. Just because the wind is blowing
fifty knots and there are twenty foot seas doesn't mean that all of that
energy has to climb on board your yacht. You can heave to, use drogues
or even parachutes to decouple the energy of the storm from your yacht.
3. Reduce your yacht's energy (speed) to the
smallest amount possible consistent with good seamanship. When you
stop your yacht or reduce its speed, you are stepping away from the edge of
disaster. You are saying goodbye to brinksmanship and hello to good
Inexperienced mariners need to understand that in non-breakings seas,
water doesn't move horizontally. It moves vertically. There
is no horizontal displacement of the water in a non-breaking wave. If
you look at a single molecule of water in a wave, the water molecule moves
up and down in a trochoidal pattern rather than moving in a horizontal
direction. In non-breaking waves, the water molecules are riding an
elevator up and down as the energy wave passes through the sea. When
you watch the oncoming waves in a storm, it's not water that is coming
toward you, it's an energy wave that's moving in your direction. The
water molecules are just moving up and down, whereas, the energy wave is
moving toward you at 20 - 25 knots. As long as you don't couple
all that energy to your yacht, the energy will pass harmlessly under your
hull. But if you start sailing and decide to surf down the front of
the energy wave, then you can couple large amounts of wave energy to your
yacht and it can even reach dangerous levels that can cause you to broach.
In non-breaking seas, if you don't couple into the energy wave, you will do
In non-breaking seas, there is no excuse for getting into trouble. If
you get hurt, it's because you have made bad choices that allowed your yacht
to couple into the energy of the non-breaking seas. You are guilty of
pilot error and any damage that you sustain was preventable.
Breaking seas are an entirely different story. There is horizontal
displacement of tons of water heading straight for your yacht. When
all that water hits your yacht, it transfers massive amounts of energy
to your hull, and if you can't dissipate that energy in a safe manner, big
problems will happen.
To deal with breaking seas, you must prevent or minimize the energy couple between the
seas and your yacht. That's where parachutes and series drogues can
save you. They can keep your kinetic energy at close to zero and
decouple the energy of the seas from your yacht.
Parachutes essentially stop your yacht and reduce the
kinetic energy of your yacht to zero. Parachutes also keep the bow of
your yacht into the seas (easily done in a catamaran) and this reduces the
coupling of storm's energy to your yacht as well. The bows present a
small surface area to the sea and makes it more difficult for seas to
transfer their energy to your boat.
A series drogue will slow you down to a few knots, and if a massive wave
strike happens, it will hopefully keep your kinetic energy at safe levels.
Breaking seas are dangerous, and only good seamanship will get you safely
through a storm with large breaking waves. When the breaking seas get
really big, you better have your parachute in the water or be towing a
powerful drogue behind your yacht.
STAY OUT OF BLACK HOLES WHERE PEOPLE GET HURT YEAR AFTER YEAR
People frequently and predictably get hurt in "black holes" every year.
These places include the Agulhas current in the Mozambique Channel, the
Agulhas Plateau, the Gulf Stream, the no mans land between New Zealand and
the South Pacific, and the Tasman Sea. These and other black holes can
swallow you up without a trace. If your boat and crew are not up to
sailing through black holes, don't go there. You can sail all the
way around the world in the trade winds without sailing into any black holes
if you go up the Red Sea.
DEALING WITH BLACK HOLES
1. You need to have a working engine in good condition to push the
odds in your favor.
2. You need lots of fuel.
3. Synchronize with a weather window.
4. Turn around, hold position, or alter course if conditions are
5. Stay to one side of any storm coming your way.
6. Have drogues and parachutes prepared ahead of
time and ready to go.
Two times I sailed through black holes from Fiji to New Zealand. Both
times I had a good trip because I left Fiji on the back side of a low, and
then I motor sailed through the oncoming high, and I arrived in New Zealand
just before the next low pressure system came across the Tasman with stormy
seas. Those people who refused to use their engines and instead sailed
all the way to New Zealand ended up taking ten days for the voyage rather
than seven, and many of them suffered damage en route. Each year that
we made the trip, there were one to three people lost in stormy seas.
On our first trip, a steel yacht was rolled and a family of four was run
down by a ship in stormy seas with the loss of three lives.
When I head through a black hole, I don't dilly dally.
I put the hammer down, and if there isn't sufficient wind, I turn on my engine because
I don't want to spend any time longer than necessary sailing through black holes.
When I know that I am going to sail through a black hole,
I pre-rig my parachute bridle on the bows so that it is ready to go if I
need it. I also pull all of my drogues, parachutes, tethers, floats,
rodes, and bridles out of the lockers before I set sail, and I put them on
the cabin sole in my salon where they are easily accessible. I put a
couple of cushions on the pile of safety gear, and I make a large bunk out
of it. If it becomes necessary to deploy a parachute or a drogue, I
move the gear to the cockpit where I assemble all the components for rapid
and easy deployment.
IT'S NOT THE WIND THAT WILL GET YOU IN A STORM. IT'S THE SEAS THAT
WILL CAUSE THE BIGGEST PROBLEMS. STAY TO ONE SIDE OF STORM TRACKS SO
THAT YOU GET SEAS MOSTLY OUT OF ONE QUADRANT.
Moitessier's Plan - When sailing in the southern ocean, he sailed away from
the path of the oncoming gale for the first half of the storm, and then he
turned toward the storm's center after the center passed by. This
helped him remain in less confused seas. He wanted to experience seas
from only one quadrant.
Never allow a storm to pass directly over you offshore unless you want to be
pummeled by seas from every direction.
WHEN YOU MAKE A MISTAKE AND GET CAUGHT IN A STORM, HERE'S WHAT TO DO:
1. Deploy a parachute. A parachute stops your boat
reducing your kinetic energy to zero. It decouples the storm's energy
from your yacht. It holds the bows into the wind and seas making it
harder for the storm to take control of your yacht.
Parachutes work exceptionally well with catamarans. The wide beam of a
cat allows the use of a bridle that keeps the bows of the cat pointing
directly into the seas. Furthermore, there is no rolling of the
catamaran when lying to a parachute sea anchor. We have used a
parachute sea anchor only one time, and it was pure magic. It turned a
bad situation into a "no worries mates" situation.
2. Deploy a drogue. Drogues slow your boat down and may
even protect against wave strike in breaking seas if you use a powerful
drogue. The Jordan Series drogue is extremely powerful, and if your
stern and cockpit can handle breaking seas. the Series Drogue can maintain
your kinetic energy at safe levels even with a major wave strike.
Drogues work well on catamarans for several reasons.
The twin hulls of the catamaran impart exceptional directional stability to
the yacht, and the cat will run downwind like it's on railroad tracks.
Furthermore, the following seas are able to slide under the elevated bridge
deck rather than climb on board. Seas that might climb up the stern
and fill the cockpit of a monohull will pass harmlessly under the bridge
deck of a cat.
Storm management is about energy management. If you control the
energy of your yacht, and if you decouple the energy of the storm from your
yacht, the odds of survival are in your favor.
SEA ANCHOR CHAINPLATES
I've heard some experts say that the forces generated by the pull of a
parachute sea anchor will pull your cleats right out of the deck. If
you attach the parachute bridle to the cross beam of your catamaran, it will
pull the crossbeam out of the bow.
I created my own answer to this objection. If you examine these
pictures, you will see the parachute sea anchor chainplates that I put on my
bows for use during storms, and I also sometimes use them at anchor in
harbors if a major storm is headed my way. They create a chafe free
way to attach a bridle to Exit Only.
These chainplates are twenty-five inches long on deck and consist of six
millimeter thick stainless steel. On the underside of the deck is the
same size of stainless plate, but it is only twenty inches long. Large
bolts go through the deck and through both chainplates, and there is nearly
zero chance that these chainplates will ever move. If they move, it's
because both bows will have been pulled off the boat.
Welded down both sides of the chainplate and sticking out in front of it is
a stainless steel bail that is about as thick as my finger. The
part of the bail that sticks out in front of the bow is where I attach my
parachute bridle using d-shackles that I wire closed after the bridle is in
place. The bridle has large stainless steel thimbles on it so there is
no chafe on the arms of the bridle where they are shackled to the bails.
When we left New Zealand expecting to get hit by a low pressure area or
caught in a squash zone, I attached my parachute bridles to the bail of the
parachute anchor chainplate on each bow before I left port. Everything
was ready to go if we needed to deploy the chute. When we got caught
in the squash zone, we shackled the parachute sea anchor rode to the already
attached bridle and we quickly and easily deployed our parachute. It
wasn't that big of a deal because everything was prepared in advance and we
had tons of confidence in our gear and boat.
The bail that is welded to the sea anchor chainplate proved to be immensely
strong. When we were anchored in Bequia in the Caribbean, a 115
foot long charter power yacht lost control of their vessel while raising anchor, and
they plowed into our port bow. Fortunately, the sturdy bail on the sea
anchor chainplate acted like a bumper putting a dent in their wayward bow
which protected us from any damage to our hull. I have no doubts about
the strength of our sea anchor chainplates and welded bail on our bow
because it easily absorbed and survived the hit by that mega yacht.
Our chainplates and sea anchor bridle system isn't going anywhere.
The bail was also useful when we were crossing the Indian Ocean dodging
giant logs after the tsunami. We occasionally hit tsunami debris that
was small, but when we got into logs that were bigger than our boat, I had
to do something to protect our bows in the event of a collision with a tree.
I used two long wooden oars to protect our bows. I passed the handles
of the oars vertically through the bails on the bow, and then I lashed the
oars into place. So I had heavy duty oars running down the full length
of the bows, and if we hit anything, the oars would take the impact and
spread the force of the impact so a hull penetration would not occur.
One oar survived intact, and the other oar ended up being badly splintered
by the time we were through the tsunami debris field. Even with those
precautions, we still had some tsunami related bow damage.
If we did not have those bails sticking out in front of our bows, we
would not have had a place to securely attach those oars on the front of our
bows. It's quite possible that we could have had some major tsunami
related damage if those oars couldn't have been lashed in place.
I love my sea anchor chainplates and bails. They saved me north of New
Zealand in a squash zone, they saved me from serious tsunami damage in the
Indian Ocean, and they saved me when I was hit by a mega yacht in Bequia.
Heaving To - The Venturesome Voyage of Captain Voss
If you want to read a good book that tells about heaving to as a way of
decoupling your boat's energy from the energy of stormy seas, read "The
Venturesome Voyage of Captain Voss." It's an awesome story by a
man who sailed in the high southern latitudes and mastered the art of
heaving to. He did it often, and he did it well.
Heaving to works because it does two things. It reduces your boat's kinetic
energy as close as possible to zero, and it creates a protective slick to
windward (a zone of turbulence in the water on the windward side of your
boat) as you slide to leeward in a square drift. Energy waves don't
propagate well into that slick zone of turbulent water and plenty of
mariners will testify that approaching waves die out when they hit that
turbulent zone of water to windward when they are properly heaved to. They
report that breaking waves pass in front of the boat and by the stern, but
the waves coming toward their beam diminish significantly in the zone of
turbulence. That zone of turbulence is a killer of breaking seas, in a
similar manner to the zone of turbulence behind a ship where the seas are
quite flat although surrounding seas are large.
The protective effect of parachutes comes from three factors. First, the
chute takes your kinetic energy down close to zero since your speed is close
to zero. Second, because it holds you relatively stationary, it's harder for
the seas to transfer their energy to your yacht. And third, the parachute
creates turbulent water - a turbulent slick - directly to windward, and seas
coming from that direction lose their power when they traverse the disturbed
water created by your chute. When you look at an aerial photo of a parachute
sea anchor at work on the cover of the Drag Device Data Base book, you can
see the parachute close to the surface being slowly dragged through the
water in front of the yacht. When we used our chute we dragged the chute
about a half to three-quarters of a mile in 19 hours. I am sure the chute
created a zone of turbulence to windward directly in front of our yacht, and
I suspect that it helped diminish the power of oncoming seas. It kind of
puts you in an "Alley of Lower Energy" that saps the strength of oncoming
seas. You are in the zone of disturbed water that becomes your port in the
Parachutes work extremely well on our catamaran, and I am not sure which of
the three effects are most powerful during a storm. It's likely that all
three effects are important to some degree, and they are cumulative as well.
Read the Venturesome Voyage of Captain Voss and be amazed at the
power of heaving to. I am sure that Captain Voss would say reduce your
kinetic energy as close as possible to zero by heaving to, and then watch
the turbulent slick to windward protect your boat from the power of oncoming
WHEN TO DEPLOY CHUTES AND DROGUES
Don't wait until it's blowing seventy knots to deploy a parachute or drogue.
If weather fax and all available information indicates that you will be in
serious trouble, it makes sense on a boat like Exit Only to deploy the chute
while it's still easy to do. Its similar to preparing for a tropical
depression or hurricane when you are anchored in a harbor. You know what is
coming, and you don't wait to go out and anchor until it's blowing sixty
If it became necessary to change strategy from a parachute to a drogue or
vice versa, I was prepared so that deploying them wouldn't be an ordeal.
When I headed offshore, I had the chutes, drogues, and all associated gear
pulled out and ready to hook up and deploy before I set sail. If I needed
it, I would pull the gear out of my salon, assemble it in the cockpit and
rapidly deploy it.
Deploying a parachute was easy because I already had a bridle attached to my
bow before I headed offshore. Deploying a drogue was easy because I was in a
catamaran with port and starboard winches in the back of the boat and
setting the drogue was quick and easy.
The ease of deployment depends a great deal on preparation and how you have
set up your system. For us, all the components were available and ready to
go. All I needed to do was assemble the components with shackles and seizing
ALL YOU CAN DO IS ALL YOU CAN DO, BUT ALL YOU CAN DO IS ENOUGH
Don't wait until you're in a storm to figure out how you'll deal with it.
Make your preparations ahead of time and have a plan. Storm survival
isn't rocket science; it's mostly common sense. If you have a
seaworthy vessel, a parachute, a powerful drogue, and don't panic, the odds
are in your favor, and you'll the survive the savage seas. So drop
your dock lines and pull up your anchor. It's time to sail on the
ocean of your dreams.
SCHEMATIC DRAWING OF MY PARACHUTE SEA ANCHOR DECK CHAIN PLATES
Some people have requested a schematic drawing of my parachute sea
anchor deck chainplates that I had fabricated in Whangarei, New Zealand.
The chainplates were made of stainless steel flat bar, and the bail was made
of stainless steel rod. The rod was bent into a round shape and then
welded down the sides of the chainplate. The dimensions of the
stainless steel flat bar are as follows.
The flat bar on the deck as approximately 24 inches x 4 inches x 6 mm thick.
The flat bar backing plate under the deck was approximately 20 inches x 4
inches x 6mm thick.
The parachute sea anchor chainplates are definitely overkill, but they are a
fool proof, chafe free way to attach a parachute sea anchor bridle on our
catamaran. They will never pull out of the deck with the four large
bolts going to the large backing plates.