Boathandling

How to, well, SAIL!

Max Ebb on Squalls

Squall Strategy

Re-printed with permission from Latitude 38, July 1994.
Copyright Max Ebb Publications and Latitude 38, 1994

"What's the event tonight?" I asked the bartender. "I had to
drive all the way back to the second overflow parking lot to find
a space!"
But the bar was almost empty. Just a few people I didn't
recognize buying drinks, and a member serving.
"It's the weather briefing for the race to Hawaii. Standing
room only in the dining room."
"Ah, that explains it. Big entry list this year. Who's
speaking?"
The speaker was a well-known name in Transpac navigation,
all the more reason for the full house. So I ordered a gin and
tonic for myself and wandered towards the dining room, to see if
I could squeeze in for the rest of the presentation.

"If you're on a sled," advised the speaker, "you can
actually sail as fast as the squall is moving. VMG downwind will
be about half the windspeed, with no upper limit."
He was referring to a table of numbers projected on the
screen, showing the tacking angle, apparent wind angle, boat
speed, and VMG for a large ultralight.
"The squall typically moves at 15 knots, but the wind in the
squall is around 30. That's enough to get you down the wind fast
enough to stay in the area of strongest wind, so you can actually
jibe back and forth across the face of the squall many times.
Remember, the object is to stay *in* the squall"
This generated a chuckle from the audience. Having seen the
entry list, I knew that most of them were cruisers before racers.
The next chart flashed up on the screen, the numbers for a much
older and heavier 40-footer.
"But in a slower or smaller boat, one pass is usually all
you'll get. How you exit the squall is critical."
This was interesting. I walked along the back perimeter of
the darkened room, navigating between the packed bodies and re-
arranged tables and chairs. No seats, but it seemed like it might
be worth standing and listening for a while.
"On a slow boat - and that means anything but a sled - you
should generally `exit stage left' when the squall ends. That is,
leave to the left, on port pole. Never get caught right on the
ceterline of the squall's track behind it, or to the right. And
especially not just before dawn! On the average, the squall wind
will be a starboard-tack lift, for reasons that I explained
earlier. So you'll probably have jibed onto port pole anyway.
Once you leave the squall, you want to get away from the light
air behind the squall as quickly as you can."
It sounded like I had missed something important.
"Rule of thumb:" summarized the speaker - "Once you're out
of the squall itself, if you want the wind conditions to change
get on port tack. If you want them to stay the same, sail on
starboard. This is also the rule of thumb for increasing your
chances of staying under the 'wind stripes' that you'll see as
lines of clouds during the day."
"Why?" I thought to myself. I had definitely missed
something important, walking in in the middle of the talk.
"Another rule of thumb." he continued. "If you're in a sled
and are trying to jibe back into the squall, jibe as soon as you
get headed. It sounds crazy to jibe on a header - but I've
repeatedly observed the wind direction aimed inward towards the
track of the squall. The header is often the first indicator that
you're getting to one side of the strongest wind, and it's time
to go back."
Just about everyone in the room was taking notes furiously,
copying down a diagram showing wind speed and direction around a
squall cloud.
"I don't know why this happens," he confessed. "You'd think
that the strongest wind would just radiate outward from the
center of the squall. But for some reason, the wind is directed
inward like this."
He emphasized the wind arrows on his diagram, drawn in a
"toed-in" orientation on the left and right front corners of the
squall.

As my eyes became adjusted to the low light level, I could
pick out many of my sailing friends in the crowd. There were a
few of my competitors from the YRA fleet, and the handful of
yacht club members that had berths on the Hawaii race were
scattered in the crowd. There was my sailmaker, over by the wall
on the right. And even naval architecture student Lee Helm, who
sometimes can be persuaded to crew for me, was over on the left
side of the room taking notes along with all the others.
"Maybe you can explain this phenomenon," the speaker asked
the sailmaker.
All eyes were on the sailmaker, himself a veteran of many
successful races to Hawaii. Lee noticed me standing along the
back of the room, and she waved acknowledgment when we made eye
contact.
"Oh no," answered the sailmaker. "I know enough to not guess
at questions like this, especially in this crowd!"
"Anyone else?"
Now the room was silent, and I saw the sailmaker looking at
Lee. I looked at Lee to see if she would respond. She looked back
at the speaker. The speaker looked back at Lee. I looked at the
sailmaker again. He shrugged. Lee shrugged. The speaker shrugged.
And for good measure, I shrugged.
"Let's take a 10-minute intermission," announced the
speaker. "After that we'll cover wind stripes, effects of
tropical storms, and best approaches to the finish."

The house lights went on, and a large number of people made for
the bar. I made my way over Lee Helm's table, borrowing a
temporarily vacant chair.
"I'm surprised you didn't offer an explanation for that wind
shift question," I said as I sat down.
"Like, I'm just auditing this class," she joked. "Collecting
those `rules of thumb.'"
"Do you have a spot on the race this year?"
"I wish. But like, I really have to finish my thesis this
summer. So I'm on the beach again. I mean, I'll be up for it next
year, though. Especially if you know someone doing the race to
Tahiti..."
"I'll be on the lookout for a berth for you, Lee. But I
still can't believe you don't have an explanation for that wind
shift."
"For sure, there are ways to explain it. The main thing is
to think of systems of convection cells, instead of just a single
source of wind from an isolated downrush column. When one
convective cell is collapsing, it's almost certainly triggering
new ones ahead of it. So a squall system often resembles a kind
of dipole, a source-sink pair with the strongest wind right
between he two."
"Ah ha! Of course!" exclaimed a racer who was sitting at the
same table, until now absorbed in studying the notes from the
previous part of the lecture. "If you simperimpose a dipole flow
field on the surface wind - taking into account the veered upper
flow - you get exactly the wind shown on that last diagram!"
"Wait, wait, back up," I said. "What on earth are you
talking about?"
"Okay, Max," said Lee patiently. "I'll try to explain this
for the differently clued."
She turned over the page on her yellow note pad, and drew a
graph showing temperature versus altitude.
"The new word you need to know is *lapse rate*. This is the
observed vertical temperature gradien in a column of air, and
it's typically about 3.5 degrees Fahrenheit per thousand feet of
altitude. It's like if you sent a thermometer up in a balloon,
and measured temperature with respect to altitude as the balloon
went up, you like get this line."
"Okay, I'm with you."
"Cool. Now, there are two more lapse rates to deal with, the
*dry adiabatic lapse rate* and the *wet adiabatic lapse rate.*
These refer to the rate at which an imaginary piece of air would
change temperature if it's moved up or down without any heat
being allowed to flow in or out - hence `adiabatic.' A typical
value for dry adiabatic lapse rate is like 5.4 degrees per
thousand feet. So you start with a container of air, move it up a
thousand, let the container expand to match the reduced pressure,
the temperature will be drop by 5.4 degrees. That's for dry air -
if the humidity in the air is 100% when you start, then some of
the water vapor will be forced to condense, because at the lower
pressure the air has less capability to hold water vapor. This
involves a change of state for the water vapor - from gas to
liquid - and the heat of vaporization is released into the air
when the water condenses. This keeps the air warmer, so the wet
adiabatic lapse rate is less than he dry rate - typically 3.2
degrees per thousand feet."
She drew two more lines on her graph, representing the two
additional rates of cooling.
"Now, the good stuff. Suppose it's a typical day, and the
actual measured lapse rate is the average 3.5. If the surface
temperature is 75 degrees, what would happen if you took some air
from near the surface and raised it a thousand feet?"
"Dry air or wet air?" I asked.
"Good question! Let's say dry, for now."
"Okay, you said the dry rate was 5.4 degrees per thousand
feet, so it cools 5.4 degrees, and end up at just under 70, at -
let's see - 69.6 degrees."
What's the temperature of the surronding air at that
height?"
"I get it," I said. "The surrounding air is 3.5 degrees
cooler, according to the lapse rate curve, so the surrounding air
is at 71.5 degrees. The air that we lifted up is now cooler than
the surrounding air, so it would sink back down."
"Very good! We have stable air. No convection cells here.
You remember from the last time we went through this, huh?"
"Okay, but what does this have to do with squalls?"
"Hang on. What if you have air that's fully saturated with
water, and raise it a thousand feet?"
"Use the wet lapse rate," prompted the other racer at the
table, when I hesitated."
"Thanks," I said as I did some more arithmetic in may head.
"Now the air only drops in temperature by 3.2 degrees, to 71.8."
"And?" asked Lee.
"Compare with ambient," suggested the racer.
"Oh, I see. It's a little warmer than the air around it this
time, so it would rise up."
"So?"
"So, I guess it would keep rising."
"Which means the air is unstable. That's why cumulus clouds
billow up - the moist air keeps rising, water vapor adding heat
to the rising column of air. Whenever the lapse rate - what you
measured with the balloon - is steeper than the adiabatic rate -
wet or dry, as appropriate for the altitude and the amount of
moisture - the air will be unstable. Push some air up, and like,
it keeps going up. Push it down, and it keeps sinking."
"Last time we discussed this you mentioned the lava lamp." I
noted.
"Right. If heating near the ground causes the measured lapse
rate to be steeper than the dry adiabatic lapse rate," added the
other racer at the table, "even dry air will be unstable, and
boil up in a column of rising air, or a thermal. I know all about
this stuff because I fly gliders. When the air reaches `cloud
base,' pressure drops to where the water vapor saturates the air,
then the wet lapse rate takes over, and it becomes even more
unstable. The thermal in the cloud is generally stronger, and
more turbulent."
"Okay, back to squalls," said lee. "The ocean surface is
heated slightly by the sun during the day, but it doesn't change
temperature nearly as fast or as much as the air. At night the
upper air cools, but the air near the surface stays warm. The
actual lapse rate becomes very steep - relatively warm at the
surface, much cooler a little way up - so the air is unstable,
even the unsaturated `dry' air right at the surface is unstable.
Rising columns of air form. But the air doesn't have to rise very
far before it becomes saturated, causing it to cool at the
slower, wet adiabatic rate, which makes it even more buoyant
relative to the surrounding air, which makes it rise even faster,
which makes it even more buoyant still. You have a humongous
towering cumulus cloud, transfering hot air up from the surface,
trying hard to bring the temperature gradient in the atmosphere
back to normal."
Lee was gesturing with her hands as she spoke, trying to
depict clouds rising to the stratosphere.
"And it works the other way too." she continued. "When the
moist air at the top of these clouds cools down, it's ready to
start falling. Extra liquid water in the form of cloud droplets
and rain are re-evaporated back into the descending air,
effectively refrigerating it as the pressure increases. The
`downrush column' picks up speed, and as long as the lapse rate
of the surrounding air is steeper than the wet adiabatic lapse
rate, the downdraft air just keeps sinking faster as it falls
through the cloud. If there's rain falling out of the cloud, then
the wet rate applies right down to the surface, because there's
still water evaporating into the air."
"That checks with my experience," I noted. "Cold rain in
squalls."
"That's the standard description of how an isolated squall
works," said Lee.
"Right," added the racer. "They build all evening, and start
collapsing later at night or in the early morning hours. The
biggest squalls of all are the ones that hit just before dawn."
"So you'd think," Lee continued, "that the wind field around
a squall would be a strong outward flow of cold air, from the
downrush column hitting the surface and spreading out in all
directions. I mean, you have to add to that wind pattern the
existing trade wind field, so the two winds reinforce each other
in front of the squall, and cancel out behind it leaving you
becalmed. You also have to add the wind component from the motion
of the squall cell itself, which will be deflected to the right
relative to the surface wind. That's because the upper air
follows the isobars, but down low the wind is slowed by surface
friction and tends to be distorted along the pressure gradient,
away from the center of the high."
"That explains the usual starboard-tack lift in a squall,"
said the racer. "At least it's a starboard tack lift slightly
more than 50% of the time."
"I'm not sure I got that last part," I allowed, "but
everything else agrees with what the books say. The squall
behaves like a strong downrush of air, fanning out from a point
right under the clouds, adding to the average wind in front and
subtracting from the wind in back."
"Except when it doesn't," said the racer/pilot. "The shift
is to the right most of the time, but how do you explain the
times when it shifts the other way? And how do you explain those
toed-in wind arrows on that diagram?"

"There's a few more things going on," said Lee. "First off,
you really don't know where the convection cell is in its cycle
of developing and collapsing. That affects wind speed and
rainfall. But more important, squalls hardly ever exist as
isolated cells. The night air is unstable, and when the downrush
air turns horizontal and flows out in front of the squall, it
forms a cold wedge, like a miniature cold front, that lifts a lot
more warm air up from the surface. This sets off a new convection
cell of rising air immediately in front of the squall."
"So the air from the downrush gets sucked right back up into
the new thermal?" I said, as the idea finally sunk home. "Now I
see why the wind direction turns inward!"
"Not exactly. I don't think the downrush air is going to
warm up quickly enough to power a strong upward convection. So
it's not a true dipole flow field, in that sense. But I think
there's converging flow into the new cell right above the
downrush air, and this tends to deepen the layer of cold air,
making it converge into a narrower band of wind like the diagram
shows."
"Interesting theory," said the other racer. "It suggests
that the strongest squalls would be double cells like that, to
get the effects of downflow and upflow combined."
"Does it explain the old rhyme about wind and rain?" I
asked.
"What's that, Max?"
I recited a rhyme I remembered from an obscure book about
nautical folklore:

"First the rain and then the wind,
Topsail sheets and halyards mind.
First the wind and then the rain,
Hoist your topsails up again.

"Owe! That's a rhyme?" Lee scoffed. "It uses `wind' and
`mind,' then `rain' and `again.' I mean, call the rhyme police!"
"It must be very old," noted the other racer. "Those words
might have sounded okay as rhymes a thousand or more years ago."
"But the amazing thing is," I said, "it seems to be true!"
The strongest squall winds come right after the rain. According
to the usual description of a squall, it always seemed to me that
the wind should hit first."
"It checks with my dipole model," said Lee, "despite the
dorky rhymes. Like, you'd expect to find rain under the new,
strongly driven convection cell in front of the main squall
cloud. Then the strongest wind would follow the rain. But if the
rain comes after the wind, then the squall is already over and
you're in for a period of calm in the squall's wake."

"So how can we use all this to advantage during the race?"
we asked.
"By understanding that some clouds are going up, and some
are going down. Some people like to think of cumulus clouds as
pistons - when one collapses in a squall, it pushes another one
up. Then there's the gravity wave theory. Researchers have
actually identified big atmospheric waves, like water waves,
causing new convections cells to appear near existing cells. So
it gets pretty gnarly."

Meanwhile the room was filling up again, but fortunately
whoever had a prior claim to my chair had found a better view
from another part of the room. Lee flipped her pad to another new
sheet of paper as the lights dimmed.
"Is any of this actually going to help us get to Hawaii?"
the racer asked again.
"For sure," said Lee. "Just use all the rules of thumb!"

max ebb

RULES OF THUMB FOR SQUALL TACTICS:

1) "Incoming lane" for squall: squall should be just abaft the
beam on starboard tack.

2) Jibe on headers to stay in the squall (sled only).

3) Always exit stage left.

4) Don't be anywhere near the last squall just before dawn. Wind
dissipates at first light.

5) Best lure: blue & white feathers with silver head.

Spinnakers by Kame Richards

TIPS AND TRICKS FOR SPINNAKER HANDLING
by Kame Richards

[The following is an article which I wrote for the RACE GUIDE for the 1998 WEST MARINE PACIFIC CUP.]

OVERVIEW

The following is a list of suggestions on how to handle a spinnaker in the West Marine Pacific Cup race to Kaneohe. Keep in mind that spinnakers are fairly large sails, and are quite capable of dragging a sailboat a long distance, whether the boat is right side up or sideways!

One of the things I admire most about the Pacific Cup Yacht Club is that they make a serious effort to help you learn how to race your boat better.

You are about to embark on a 2200-mile long intensive sailing lesson (not to say immersion). It would be unfortunate to sail that far and not substantially improve your sailing skills.

SPINNAKER SETS

First of all, know all the halyards are straight and clean before your first set the spinnaker. If it is dark, use a bright flashlight to check things out at the masthead. (This should be done every morning and afternoon as a matter of course.)
If you will be doing spinnaker peels (see below), anticipate the first spinnaker change so the halyards will still be clear after one spinnaker change.
On a race like Pacific Cup, I prefer double sheets and guys, even on fairly small boats. This means there is a sheet and a guy on each clew ring in the spinnaker. I also prefer independent shackles (or knots) to attach each of the lines to the clew ring, with the sheet fastened above the guy. This makes it twice as hard to flog off both lines. The sheet needs to be over the guy to make dip pole gybing run smoother. I also prefer knots in the end of the spinnaker gear, but the gear must be long enough for the clew of the sail to wave like a flag in front of the boat. This means the sheet is two times the length of the boat. The length of the guy depends on where you lead your guy, and whether or not you use a turning block. I know the books tell you to never EVER put knots in your spinnaker gear, but it is awfully hard to take the sail down if all the gear has some how been allowed to run free, and now the spinnaker, AND all the sheets and guys are streaming down wind from the masthead!
It's okay to set the spinnaker right from the bow pulpit. This means there will be less afterguy to bring in. The halyard will also go up faster because it will not be sliding up the outside surface of the genoa.
If you are using a spinnaker sock, it seems best to connect the halyard to the top of the sock, pull the halyard up, straighten out any twists in the sock, connect the sheets and guys, then haul the sock up to fill the sail.
In the event you are using a roller furling jib, I think it would be best if you drop the sail onto the deck after you set the spinnaker rather than furl up the jib. Reason 1: The roller jib is quite heavy, and it is not wise to carry that much weight (a) that high in the air and (b) that close to the bow. Reason 2: If you get a spinnaker wrap, it will be much harder to undo because the spinnaker cloth will not slip off the UV cover material on the jib as easily as it slides off the aluminum foil of the furler.

SPINNAKER GYBES

On the boats I've gone on in the past, we have found it best to assign people to the individual jobs for gybing, independent of being on or off watch. This means the same person will be in the bow, on the topping lift, in the cockpit, etc. You may want to appoint two drivers so the one who was completely asleep when the gybe was called doesn't have to try to steer while half asleep!
If it is fairly windy, two-pole gybes are something to consider. In this case you rig a second pole, including a topping lift and a foreguy. Connect the new pole to the lazy guy, top it up, square it back and trim in the new foreguy. Now the spinnaker is held solidly from three corners and consequently will hold very still during the gybe. Now gybe the mainsail over to the other side, and take down the old pole. The problems / dangers of this style of gybe is that if you round the boat up or down, you will stick a pole in the water, and probably break the pole, or worse, the mast. You also must be careful setting the new pole and dropping the old pole, because it is momentarily pointing directly into the spinnaker, and if they touch, the chances of tearing the sail are very high. Another problem is to be sure that the two inboard ends of the poles don't bind on each other while you are working with them.
If it is very windy and you feel you can't complete a gybe without breaking something, the "chicken gybe" is a safe way to get the job done. In this case you drop the spinnaker, and then actually TACK the boat, and then re-set the spinnaker. In my experience, if it is so windy that you elect to chicken gybe, you will be smart enough to not try to reset the spinnaker immediately.
If you are using a sock, consider pulling the sock down to contain the spinnaker and lowering the pole onto the foredeck. Then gybe the mainsail, connect the spinnaker pole onto the new afterguy, and reset the spinnaker.

SPINNAKER CHANGES

The most conservative spinnaker change is the bald headed change. Get the new spinnaker up on deck, with the bag fastened down and the corners organized. Strip off the old spinnaker (see "spinnaker drops" below), put the same gear on the new sail, and send it right back up again. This provides an opportunity to change spinnaker halyards.
Spinnaker peels take a little more time and a little more orchestration, but when properly done, the boat is never without a spinnaker that is full and pulling. In the peel, you rig the new spinnaker with a new (clear) halyard, a sheet, and a "tag line" which will temporarily hold the tack of the sail. (Rig the tag line as follows: a snap shackle at the free end, clove-hitched to the headstay at shoulder height with the snap shackle hanging two feet down, with the other end securely fastened to the bow cleat to prevent the whole arrangement from sliding up the forestay.) The new spinnaker is hoisted and trimmed. When it is drawing, the old spinnaker is tripped from its afterguy. It will rotate off downwind and act like a flag flying from the halyard and the sheet, where it will hang out for a while. Now ease the spinnaker pole toppinglift and afterguy so the guy can be connected to the spinnaker tack. Take the slack out of the afterguy, and trip free the tack of the sail from the tag line. Now square the pole back to its proper sailing position. Not until the new spinnaker is fully trimmed is the old sail dropped. Finally do what needs to be done to straighten out the spinnaker halyards. Occasionally this requires sending someone to the top of the mast.

SPINNAKER DROPS

You must be sure the halyard will come down uninterrupted, so flake out the halyard tail, or drop the tail over the side so you know it is straight (literally!), and can't get tangled up. While you are at it, be sure the afterguy and lazy sheet are organized too.
In order for the crew to pull in the spinnaker, it must completely collapse. This should happen before the halyard is let down.
- One way is to ease the afterguy forward until the pole is near the forestay, then let the afterguy run completely free. "Free" means taking all the wraps off the winch and letting the line go.
- Another way is to trim in the sheet, ease the pole forward, and bear the boat off. This will move the spinnaker into the dirty air behind the mainsail, which will cause it to collapse. Now run a whole bunch of the halyard, watching the crew gathering the spinnaker to be sure the sail doesn't fall into the water. There are two potential problems to this style of drop: (1) If you let the halyard off as soon as the sail collapses you run the risk of the spinnaker blowing through the foretriangle the wrong way and causing a spinnaker wrap. (2) As the sheet is trimmed in, the spinnaker is prone to round the boat up. It is essential to bear the boat off to counteract the round-up problem and cause the spinnaker to collapse.
- Still another way is to lower the topping lift and ease the pole forward so the foredeck person can reach up and trip the guy off the sail by pulling the release on the snapshackle. I would say this is my LEAST favorite method. The spinnaker pole tends to thrash around after the sail has been tripped, and I don't want the foredeck (or anyone else, for that matter!) hurt.

SPINNAKER TRIM

The spinnaker is properly trimmed if the wind is flowing just tangent to the leading edge of the sail. Don't think of the spinnaker as a bucket which "catches the wind." Just like a main or a jib, it is a foil which bends the wind, and just like a main or a jib, the spinnaker pulls the hardest when the wind is traveling smoothly across the spinnaker's OUTSIDE surface.

The sheet side:
- The luff should fold in every once in a while. This is the best way to tell that the wind is flowing tangent to the spinnakers' leading edge.
- The boat is SLOW if the luff doesn't fold in every once in awhile.
- Anticipate acceleration: When the boat speeds up, as in surging down a wave, the apparent wind will increase and swing forward. Start trimming in the spinnaker sheet as soon as the boat starts to speed up. Be sure you ease it back out as the boat slows back to its original speed.
- The driver should not steer to correct for these small spinnaker luffs. If you are the trimmer, be sure you talk with the driver so you understand the drivers anxieties about how the spinnaker is being trimmed
The guy side
- A good basic rule is to keep the pole perpendicular to the apparent wind angle, which is indicated by the wind indicator at the top of the mast.
- The pole height is determined by where (in terms of up and down the leading edge) the spinnaker first folds when it luffs. The pole is too low if the luff occurs high up near the head. If the sail is luffing relatively low, like half way down or more, the pole is to high.
- Be sure that you trim the sheet much more often than the pole. Although you can fix a collapse by easing the pole, this should be the last resort. The boat seems to lose its punch when the leading edge of the spinnaker is being constantly moved backwards and forwards.
Halyard
- It is best to keep the spinnaker halyard all the way up. It keeps the sail from moving around too much.

SPINNAKER STEERING

Fundamental to steering is realizing that every time you move the rudder, the boat slows down a little bit. So the more you can get the boat to go the way you want it to without using the rudder the better.

Anticipate steering: If the boat is straight up and down, it will tend to go straight ahead. When the boat heels left, it will turn right. When it heels right, it will turn left. As soon as the boat changes angle of heel, start putting in the steering correction. The sooner you put in the correction, the smaller the correction can be, thereby slowing you down less.
Anticipate acceleration: When the boat speeds up, as in surging down a wave, the apparent wind will increase and swing forward. Bearing off (turning slightly downwind) will reduce the chance of a spinnaker collapse...especially if you see that the spinnaker sheet is not being trimmed in at this moment.
As a driver, you need to keep your trimmer informed of how you feel. If you want the sheet trimmed a little softer on average, just ask for it. This usually starts the kind of conversation that gets your boat sailing faster.

CHAFE WATCH

In racing to Kaneohe, chances are you will sail something like 1500 miles with a spinnaker up. That is a lot of miles, and it will be a lot of hours too! It will be the equivalent of many years of racing if you just did buoy racing or the local ocean racing series. One of the ways this will manifest itself in chafe on the lines. You need to set up a 'Chafe Patrol' once or twice a day . The common places to look are:

Spinnaker sheet on the winch -- A common problem, especially with brand new winch drums, also a problem with polypropylene covered sheets. This usually is no surprise. You will see a lot of fuzz lying around the winch base!
Spinnaker sheet on the bottom edge of the boom -- For this type of sailing, the sheet should not be allowed to rub on the boom. Even on a smooth boom, you can chafe through the outside sheath of a sheet in one night. Rig a spinnaker twing or snatch block in such a way as to prevent the sheet from rubbing on the boom.
Spinnaker halyard -- Even though this might be the place you would least like to go, someone should get up to the top of the rig once a day to be sure everything is hanging together. If you have been using one halyard for a few days, you can change spinnaker halyards by sending up the inspector on a jib halyard, have them attach the other spinnaker halyard to the head of the sail, take up the load on the new halyard, ease off the old, and bring the old halyard back down to the deck...being sure everything is clean of course! Keep in mind a broken spinnaker halyard usually lands the spinnaker in the water straight in front of the boat. After you sail over it, it doesn't quite seem to work the same, even if you get all the pieces back!
Afterguy in the jaw of the pole -- Another hard place to get to, and a hard place to see, but it must be checked. One opportunity is during spinnaker changes when the afterguy is not connected to anything.

CHAFE SOLUTIONS The first solution is to not let the chafe happen in the first place. But if it has already occurred, here are some fixes:

Spinnaker sheet on the winch -- Spinnaker sheet on the bottom edge of the boom -- usually reversing the sheet will move the chafed portion of the sheet out of the actively used area of the sheet.
Halyard at masthead -- Reversing the halyard, or trimming off the top foot or two, will give you a "new" piece of line to work with.
Rigging an external halyard, which touches nothing except sheaves and a winch will chafe the least.
Afterguy in the jaw of the pole -- Again either shortening or reversing the guy will solve the problem. Or wrap the last 4" to 6" in leather.

SPINNAKER REPAIRS

You will need to have a spinnaker repair kit, which is a sub-section of the sail repair kit. The spinnaker repair section needs to contain the following:
- one quart of acetone or denatured alcohol
- masking tape / duct tape / vinyl tape and push-pins (to hold the torn sail in place while you apply the adhesive material)
- "Sticky back" Dacron tape, about the luff length of your spinnaker, 2 or 3 inches wide depending on the size of your boat. (This is NOT the same as "spinnaker repair tape." The dacron sticky back is both stronger as a material, and uses a much more tenacious adhesive than the ripstop nylon repair tape.)
- Stainless Steel round rings (in the event a head or clew ring pulls out)
- 1 inch tubular webbing, 4 to 6 pieces one to two feet long depending on the size of your boat. (to anchor the round ring to the remaining reinforcement in the head or tack)
- hand sewing kit (needed in the event the loads in the repaired area are too great for adhesives alone)
Where is the hole? If the hole is relatively close to a corner (approximately 10% to 15% of the luff length), it is more important than a hole that is further away from the corner.
What kind of a hole do you have? If the hole is about 1/4 inch in length you can pretty much ignore it. Holes of about 4 inches in length would cause me enough anxiety that I would want to get the sail down and fixed reasonably soon. With bigger holes, it becomes important to try to get the sail down quickly without making the hole worse.
Repair goals:
- The repair will be accomplished by applying the dacron "sticky back" tape across the tear. The adhesives will not stick unless the sail is clean and dry. Use the acetone or denatured alcohol on paper towels for cleaning and drying.
- For a working surface use an upside down floorboard, because the owner will probably let you stick pushpins into it, but not likely into the table or the deck. If you use pushpins for holding the repair, don't pull the cloth so tight that the pushpins tear the spinnaker anew!
- We want the repair area to be locally flat, just like before the sail was torn, so do not overlap the cloth. We want a butt joint, so the yarns on one side of the tear just touch the yarns on the other side of the tear. It is also desirable for the individual yarns to line up across the repair. If they are shifted left or right, we will end up with a pucker at one end of the repair, and the sticky back dacron tape will tend to come off the sail at the wrinkle.
- If the hole is longer than two or three feet, place the sticky back on both sides.
Procedure:
- Clean and dry the effected area with the acetone.
- Get the effected area flat.
- Cut the sticky back to a suitable working length. Longer than three or four feet becomes challenging.
- Peel back 6 inches of the paper backing at one end of your working piece.
- Carefully position the sticky-back so (1) the middle of the hole runs down the middle of the sticky back, and (2) so one end of the sticky-back will reach beyond the hole by several inches. This is best done by placing the still paper-back portion onto the hole, getting the alignment correct, and then laying down the exposed adhesive. Now working from the glued end, peel off the backing and rub the sticky-back onto the spinnaker.
- The adhesive is pressure sensitive, so press hard while you are rubbing the sticky- back down, especially along the outside edges.
- If the tear is in a high stress area, or large, use sticky-back on both sides of the spinnaker. You may also need to stitch through the sticky-back to reduce slippage.

After 2200 miles of sailing, you will have had a great opportunity to work on many of the ideas covered here. I hope this article helps you anticipate problems so they can be avoided and, most of all, I hope it helps you get to Kaneohe sooner!

For further reading...

If you are using a spinnaker sock, there is a great article on using them on our web site, www.pineapplesails.com. Point your browser at www.pineapplesails.com/downwind.htm. There is also an article on dip pole gybes, with descriptions of each step and in what order they need to be done at www.pineapplesails.com/dpg_chro.htm.