The purpose of this tuning-guide is to give our clients in the Snipe
class some guidelines on how to get the most out of their North Sails.
Follow the guidelines, but always experiment and try finding your own
trim. The weight of the crew, the balance of the boat, the stiffness of
the mast together with specific local wind and sea conditions all have
influence on the fastest and final trim.
Sailing is a very equipment intensive sport. To achieve the best
possible results we must optimize our equipment to extent that the Snipe
class rules allow. This involves taking a top to bottom look at all our
equipment and taking a "no compromise" approach.
Make sure that your hull is minimum weight (381 lbs.) and that it is as
smooth as possible. Fill and fair all imperfections in the hull. Pay
special attention to the area around the bailer.
Most top sailors sharpen the last 4-5' of the chines and the
intersection of the transom and hull in the back of the boat. This
allows the water to clear away from the hull more smoothly and promotes
planning quicker when the breeze is up.
The Mast: The mast and it's tuning are probably the single most
important thing, to good consistent boat speed in a Snipe. Presently
there are four "popular" masts in use, Cobra II, Sidewinder Sr., Proctor
Miracle and Sidewinder Junior. The Cobra II and the Sidewinder fall
into the "stiff" mast category and the Proctor Miracle and Sidewinder
Junior are so called "soft" masts.
It is important to know that no two masts are exactly the same and
each boat will need a little bit of fine tuning to get it's set up
right. It is preferable to have adjustable spreaders (both length and
angle) as you will generally want to make some adjustments as you get
your boat up to speed.
On many masts especially the stiffer models, you may want to file
down the forward part of the mast butt. This will help to induce
pre-bend in the mast especially for light air.
Boom and Pole Launcher
Most boats now use the pole launcher system and we encourage you to use
this system on your boat. It makes setting the pole much easier and
faster taking it down a cinch. We find you can keep the pole up almost
all the way to the mark with the launcher whereas with the standard pole
system you need to take the pole down rather early to stow it before
The class rules allow you to taper the edge of the boat to within 1" off
the edge of the board. You should make sure your board is tapered on
the front, bottom and aft edges. We suggest a "bullet" type shape for
the leading edge and more of a "V" shape for the after edge of the
Be sure to rinse your board after sailing in saltwater and dry it
completely. This will save it from becoming pitted with corrosion.
You may want to consider cutting out some of the board in the top of
the board where it stays inside the boat when down all the way. This
makes the board lighter and less work for the crew to lift. Overweight
boats can shave off a few pounds here by cutting away some of the top of
the board. Check the SCIRA rulebook for limitations on how much board
can be cut out.
Layout of Controls
The layout of control lines is wide open on the Snipe. We suggest
running most of the controls to the crew with the exception of the vang,
and traveler. This allows the skipper to concentrate on driving
especially at crowded mark roundings.
The Crew: Competitive crew weights range from 275 lbs. to 325lbs.
Generally you can sail lighter in flat water than in rough water.
Heavier crews will want to set their boats up for more power (see below)
where lighter crews can set up with somewhat flatter sails.
Basic Rig Set Up
With the mast down, we want to adjust our spreader length and angle.
These two things determine how much the mast will bend and how much
power will be in the sails, and how easy the boat will be to power up in
light air and depower in heavy air. Before stepping the mast check the
This dimension, measured from the side of the mast to where the shroud
intersects the spreader. For most boats this length is 16 ¾" (42.5 cm).
The length of the spreader affects the side-to-side bend of the mast
primarily. After stepping the mast and going sailing you will want to
sight up the front side of the mast and make sure it is straight side to
side from the deck to the hounds. This is very important: if the mast
is bending to leeward in the middle, shorten the spreaders until it is
straight. If the mast bows to windward in the middle make the spreaders
longer until the mast is straight.
The angle of the spreaders (tip to tip measurement) affects how much the
maximum mast bend will be. Heavier crews will want a larger tip-to-tip
measurement (stiffer mast) and lighter crews will want a smaller
measurement (softer mast). The starting point for the adjustment on this
setting is 30 11/16" (78 cm) measured from shroud to shroud with the
spreaders pulled all the way back. In heavy air or with a heavier crew
we move the spreaders forward so this measurement is 31 ½" (80 cm). In
very light air to induce more bend in the mast we sometimes angle the
spreaders back so the tip to tip is 29 15/16" ( 76 cm). Check to make
sure that the sweep aft on each spreader is the same so that the mast
bends consistently from side to side.
Mast Butt Location
You want to have your mast butt at the maximum legal forward position of
60" aft of the stem of the boat. The stem is defined as the
intersection of the bow and the deck (a point on the deck slightly aft
of the forward most part of the deck). Measure back from this point 60"
and drop straight down and adjust so the center of the mast is at this
Check your forestay so that it is maximum allowable length (mast not
touching back of partners). You will want to attached a piece of
lightweight shockcord 15" up the forestay and tie it to the bow or stem
fitting to keep the forestay snug when the jib is up. This will keep the
whisker pole from catching during jibes downwind.
Mast butt angle
Check the bottom of the mast and make sure it is cut off perfectly
square. Any deviance from this can cause the mast to not develop prebend
or develop too much. If you later find the mast does not develop enough
prebend, file the front of the mast step casting to allow the mast to
rock forward and bend more.
Shroud attachment locations: For most boats position the shrouds at
the maximum forward location of 70" aft of the stem. This will help the
main go out further downwind and increase projected sail area. If you
are having trouble developing enough power move the shrouds back
slightly which will make the mast somewhat stiffer. See figure 1.
Jib Tack Location
Position the jib tack at its maximum forward position 11" back from
stem. This helps make the sail plan longer and opens up the slot between
the main and jib. See figure 2.
Fig.1 - Shroud Position
Fig.2 - Jib tack location, all the way forward
Mast Rake Settings
Fig.3 - Mast rake measured to intersection of transom and aft deck
Fig.4 - Mast "neutral" position, note marks in front of and behind neutral mark
We use three mast rake settings depending on the conditions for
light, medium and heavy air. All settings start with a "first rake"
where the rig is just leaning forward against the shrouds and then
finish with a tensioned rake where the jib halyard is pulled on to
To start attach a 25' tape measure to your main halyard and pull all the way to the top and lock the halyard in position.
Below is a chart of the three different settings we use. All measure to the top of the transom.
| M6-X (Crosscut Mainsail) Sidewinder Gold Mast|
| Wind || 1st Rake || Tension||Staymaster ||Pin |
| 0-7|| 21'7 |
| 20 || Base|| Base|
| 8-12|| 21'6''|
| 21 - 22|| Base 5 (1 turns)|| Base 0 -0.5|
|13 - 18|| 21'5"|
| 24|| Base 12 (2 turns)|| Base 1.0|
| 18 - 22|| 21'4"|
| 25 - 26|| Base 17 (3 turns)|| Base 1.5|
| 22+|| 21'4"|
| 27 - 28|| Base 26 (4.5 turns)|| Base 2.5|
Spreader length = 16.25” / 413mm
Radial Mainsail Quick Tuning Guide (SW-4 & PR-3) - See here
It is very important to use a Holt Allen staggered hole style shroud
adjuster or Sta-Masters to have fine enough increments on your shroud
Now sight up the backside of the mast and make sure the mast is
perfectly straight side to side. If it is not you will need to remove
shims from one side and add to the other to make the mast straight. The
mast should be shimmed snugly side to side at the deck (yet still able
to move freely fore and aft).
As a last step, we want to mark the "neutral" position of the mast.
With the pusher/puller off and the mast taking it's natural position
make a mark on the side of the mast at the deck and a corresponding mark
on the deck of the boat. Mark both sides of the mast so you can see it
on both tacks. Now make marks on the deck 1/4" in front of this mark and
1/4" in back. If you feel you have an extra bendy mast (Sidewinder Jr.)
make the aft mark 3/8" behind the neutral position. See figure 4.
Now you are set up to go sailing in moderate breeze. The first thing to
do when you go sailing is to check the mast bend side to side. Sight up
the front of the mast on both tacks and make sure the mast is straight
from the deck to the hounds. If it sags to leeward shorten the
spreaders. If it pops to windward lengthen them. This is critical to
good boat speed.
With the boat hiked flat you want to have an absolutely neutral helm
in the boat. You should just need finger tip pressure to hold the
tiller. If the boat has lee helm rake the mast back. If it has weather
helm rake the mast further forward.
Your North Snipe Main comes set up for a tack line to hold it in
place at the mast. Using a low stretch small diameter line tie the tack
of the sail so the edge of the sail is about 3/8" aft of the backside of
the mast. Do not tie the tack right to the mast as this will keep the
tack from rotating downwind and make the sail full in the bottom.
The mainsheet is the throttle on a Snipe and must be adjusted
regularly to keep the boat going at top speed. The idea is to keep the
top batten on the main parallel to the boom at all time and in under 7
knots of wind have the top telltale flying 70% of the time. If the
telltale flies constantly the main is too loose. If it stalls all the
time it is too tight. Trimming the main is a constant exercise in easing
and trimming as the wind increases and eases.
In above 7-10 knots of wind the top telltale will fly all the time and the top batten should be trimmed parallel to the boom.
The main cunningham controls the fore and aft position of the draft
in the sail. Keep it loose until you begin to be overpowered and then
tighten it to open the leech of the main by moving the draft forward in
In all but the very lightest conditions the outhaul should be tight when
sailing upwind. Downwind let it off about 2-3" to make the bottom of
the main more powerful and to open up the shelf foot in the bottom of
The boom vang is used to hold the boom down when the mainsheet is
eased and to bend the mast and depower the main in a breeze. We leave
the vang completely slack until we are hiking hard. Then we take the
slack out of it so that when a puff hits we can ease the boom slightly
with out losing leech tension. As the breeze picks up more we will pull
the mast back to the aft mark at the deck and trim the vang harder. This
bends the mast and flattens the main and lets us play the mainsheet in
the puffs with out loosing main leech or jib luff tension.
Downwind, you want to use the vang to keep the top batten parallel to
the boom. Ease the vang substantially before reaching the weather mark
to make sure you don't break your boom in a breeze. In some conditions,
mostly light air and flat water, the vang can be quite loose with the
top batten outside of parallel, which allows you to sail a bit by the
lee. In heavy air this makes the boat unstable and can result in the
dreaded "death roll".
In most conditions, even heavy air, the trend lately is to keep the
traveler in the middle of the boat. Make sure your mainsheet bridle is
set up so the "y" of it goes slightly inside the boom. This will keep
the boom centered in light air without putting too much tension on the
leech of the main.
As the breezes builds and the boat gets overpowered you may find it
helpful to drop traveler until the helm of the boat is neutral and the
boat is flat.
Others will find vang sheeting preferable. With vang sheeting you
tighten the vang to keep the boon down and the tension on the leech when
the mainsheet is eased. Make sure to have the mast back at the aft mark
when vang sheeting to keep the jib's luff tight.
The mast pusher/puller controls the bend in the lower part of the
mast and has big effect on rig tension. In light air (crew inside the
boat) we push the mast forward to the forward deck mark. This bends the
mast and opens the leech of the main. It also sags the jib luff giving
you more power for light air.
As soon as the crew and skipper are sitting on the windward side of
the boat we move the mast back to the neutral mark to power up the
sails. As the breeze builds, we will pull the mast back more at the deck
to counteract the forces of the vang.
A note on soft vs. stiff masts
As the breeze really builds (15+ knots) softer mast owners will want
to keep the mast back at the aft mark. This is because the forces of
the vang cause the softer masts to really bend down low and the mast
must be held back at the deck to keep the softer masts from over
Stiffer mast owners will want to let the mast go back forward to the
neutral mark when the breeze builds. The stiffer masts do not bend as
much down low and need to be let back forward as the breeze builds to
help depower the main.
To help judge the trim of the jib your North Snipe jib has a leech
telltale sewn on it 1/3 of the way down the leech. The sail also comes
with a trim stripe on the clew. To start set the jib lead so that the
sheet is lined up with the trim lime on the clew of the jib. From there
you will want to fine-tune the lead so that the telltales on the luff of
the jib break evenly (watch through spreader window). Move the lead
forward if the top luffs first. Move the lead back if the bottom luffs
After getting the lead position correct, we want to trim the jib in
so that the telltale on the leech is just on the verge of stalling. You
will need to adjust the tension on the jib sheet constantly as the wind
builds and eases to keep the telltale just on the edge of stalling.
You may also want to make a mark on each side of the splash rail 15"
out from the centerline of the boat. The foot of the jib will fall in
this vicinity upwind and this mark can be used as a reference point for
The jib cloth tension should be tightened just enough so that there
are always very slight wrinkles in the luff of the sail. In very heavy
wind you will want to add tension and make the luff of the jib smooth to
open the leech of the sail.
Be sure your jib halyard has at least 10-12" of throw in it. You
will also want to make sure that the halyard is clearly marked at the up
position so you can easily get the halyard set in the correct position
at mark roundings.
Dead downwind let the halyard all the way off to project the jib as
far to windward as possible. When reaching with the pole up you will
find it fast to tighten the jib halyard 1/3 to 1/2 the way to tighten
the luff of the sail and make the sail more powerful and easier to steer
Please give any member of the North Snipe team a call if you have any
questions. We look forward to helping you get the most from your boat.
Good luck on the water!