Laser
Clinic Notes
General Racing Tips Steve
Bourdow
These clinic notes were sent out
on the Laser list service.
Note, they are not the property of the Iowa
Sailing Club
STEVE
BOURDOW LASER CLINIC MADISON,
WIS, MAY 24-25 2006 NOTES ON STARTING ROUTINE
LECTURE: What
is he doing at: 20 minutes before the start:
Sailing upwind. Get used to the conditions. Formulate
an overall game plan for the first beat (which side to go, shifts, current,
etc.) 10 min: Get the gun.
Get the favored end of the line. He doesn't use a compass.
Head to wind, stays there for a while with the boom gracing his head. Use the
front end of the copkit to determine line at 90 from rumbline. Compares
this line with the starting line to determine favored end. It is important
to make sure that you are on the line when doing this. To do this, squad in
the center of the cockpit, point the bow at the pin and look under your legs to
see where the committee boat is (It is easier to look 180 in the other
direction this way than by turning your head). In all, checking for the favored
side is inaccurate (no matter what method it is used), so do it several times. Next,
takes landsights to get a reference on how close to the starting line is during
the final approach. For better accuracy, one should use a landsight at the
opposite end of the side of the starting line where one starts (i.e use
the pin if you
are starting closer to the RC). Unfortunately, landsights off the committee
boat are often difficult to take, because of its size. A
landsight taken at 9 min before the start is useful 70 % of the time
(the other
times the view is blocked by other boats). Drift
under the line for about 2 boatlengths and get a second landsight (** I think he meant
"get a landsight for 2 boatlentgths"**). This is often more useful than the
"on the line" landsight, since you are likely to loose sight of it very
early in the final approach to the line (other boats will block it). Be
careful with these "off the line landsights" , because they depend on
how where you
are on the starting line (i.e. how close to the pin or the committee boat).
When starting at a different spot that the one you took your landsights from you
must take into account the fact that the landsight will represent a different
distance from the starting line. For example, if you are by the committee
boat and take a landsight using the pin by drifting 6 boatlengths down the line,
this same landsight will only represent 3 boatlengths if you start at the
middle of the line. Once he
has the landsight, he drifts down about 5 boatlengths and approaches the starting
line at about 75% of full speed, while looking at the landsight. This is to get
the feel on how fast the landsight moves with respect to the pin or the RC. Check
the favored end again. He tries to get a feel on how good the RC is and how
attentive to windshifts they are. A sloppy RC tends to try to get away
with a biased
line and that usually results in multiple general recalls and black flags.
6.5-5 min: tuning
and tactics (on what to do during the first minute after the start,
the big game plan is already decided). Where do you want to go
immediately after the start? Get
the
landsights on the laylines leading to the pin and RC. This is very
important in
pin-favored starts, but it can also help build confidence in
boat-favored starts (i.e. you
are neither barging nor being too far to leeward). Make sure to drift and
luff for a while and take this into account in your landsights for the layline. 5 min.:
get/check the gun. Go back
to check the favored end of the starting line. By now the RC cannot change
it. Also re-check land sights to see if they have changed. 3 min.:
final tune for acceleration. Simulate a start: begin with the boat almost at
a full stop and get it to full speed as fast as possible. Get the time it
takes to get to full speed. The only
control that it is adjusted in this tuning is the vang. It is desirable
to have it slightly looser than usual.
Final approach: The final 20 sec
are essential. Boathandling takes over
everything else. It is
very important to keep control of the boat, keep enough steerage way although
you might want to minimize it if you are too close to the line. Be very
weary of excessive vang tension in the pre-start period. In heavy wind, do not
power vang. Keeping the vang too tight closes the leach even if the mainsheet
is loose and this will make you slide backwards and sideways when you just try
to slow down. Also, if it is windy and you have to bail out by jibing, you are
much more likely to have break down if the vang is tight. Steering
during the final approach is mostly sculling. In Steve's opinion this is legal
as long as the tiller doesn't cross the center line. When the speed is too low
and one is about to lose control (steerage), the sculling is to be done with the
tiller to windward, turning the bow away from the wind. Most of the time one
has to keep the bow from falling off the wind by sculling with the tiller to
leeward. This can be done together with a slight trim of the sail (** I suppose
you would do that to keep your bow ahead of that of a windward boat and
preventing him from building up a hole**). If
you loose control, grab the boom with the hand,bring it to weather and release
it immediately while sculling the bow down with the tiller to windward.
The
boat will slide down in the process. Keep
the slack out of the mainsheet. This way, you will be ready to
accelerate or trim
to head up the boat. Conversely, if you want/need to lee-bow someone, choose a
boat with a loose mainsheet. They are vulnerable. Also,
avoid positioning yourself at 90 degrees of the wind and with a loose
mainsheet. It is a very vulnerable position and difficult to correct
(** I assume
that there are two problems: 1 it will eat up a lot of space to leeward to get
back to close hauled, especially if you have to build up steerage way, 2 If
someone lee bows you on close hauled you will have to turn a lot in a
very tight
space and it will take lots of sculling and lots of time **). In
very light winds it is possible to drift to windward by backwinding the
sail and
skulling with the tiller to windward. Useful to steal a hole. Within
the last minute, you must open a hole to leeward. You will use it just before
the start to accelerate. Don't try to do it to early (50 sec is too early),
especially if there are "sharks" (port tackers) ready to eat up your hole.
Turn your boat down if someone is trying to steal it (** I suppose you have to
release mainsheet at the same time if you don't want to accelerate too early **). 25 - 20-15 sec (depending
on conditions): Work hole, skull up and then "build
potential" by:
1 turning the boat down (at about 15 sec before the start)
2
trim and let the boat heel
3 hike it down to accelerate. Don't
try to accelerate without having turned the bow down (below close
hauled)
You need to get flow on the foils to have them generate lift, and the
fastest this is
achieved the better. If you stay on close hauled and simply try to
accelerate, you will sideslip a lot because it will take a long time
for the foils to
generate lift. Even
if you have a boat close to leeward, don't be afraid of waiting for
him/her to bear
off into his/her hole before you bear off into the space that this will create.
Even if he/she is late in doing so, it is usually far better than trying to
accelerate without bearing off and sideslipping behind his transom. Remember
that in pin-favored starts, the hole to leeward is even more important than when
the line is square. Also, it will take you longer to cross the line on
starboard tack). Conversely, in boat-favored starts, one reaches the
line sooner
and a good time-on-distance is critical. Finally,
don't be afraid of bailing out. For example, in pin favored starts, it
is better to recognize soon that you are not fetching the mark and bail
out to port
instead of getting into a mess at the pin and hitting it. In this situation
there are two bailout approaches:
1 slide down and tack into the space that you
have generated
2 jibe (not in heavy air).
NOTES ON LASER
TUNING AND BOAT SETUP Unlike
many other boats Lasers have a rotating mast without sidestays. Many of the sail
trim peculiarities of the Laser are due to this fact. The first
peculiarity is the sail shape: it lays out flat (as opposed to having a
built-in chamber/draft (**correct word??**) like in most boats). It has
a
very accentuated luff curve, whereas the mast has no pre-bend. The mast
bend is the main
factor in determining the sail fullness. The more bend one puts in the mast, the
flatter the sail. Never sail with the mast straight. There
are two ways of applying mast bend when going upwind: with sheet tension or with
vang tension. The sheet
pulls directly from the top of the mast and bends mostly the top section.
This flattens the higher part of the sail. When the sheet is tensioned
without any vang or cunningham, wrinkles appear starting at the luff and going
down at an angle (about 45 ). They are more dense at the higher part of the
sail where the stress is strongest. A huge wrinkle also appears going from the
junction between upper and lower section to the clew, but the sail is pretty
much free of wrinkles from there to the tack, which indicates no stress due to
mainsheet tension along the bottom section. This
large and undesirable wrinkle can be minimized by taping the joint
between top and
bottom section so that the transition is a smooth bend instead of a V shaped
one. It is best to apply the tape so that the top section leans forward, i.e. put
tape at the front end of the bottom section and at the aft end of the top
section. To
keep the main fully powered, tension the vang slightly once the
mainsheet is set. This
way when a puff hits and the sheet is eased, the boom will go out instead
of going up. Stronger
tension on the vang makes the boom push against the bottom section and bends
both the top and bottom section. This flattens (depowers) the sail. Steve
uses a 6 to 1 system on the vang, with a single (** unsure about this**) bowline
loop. He emphasized how important it is to minimize friction in the vang
system, and pointed out that some of the higher purchase systems (like
the 12:1 used
in the demo boat) where actually worse than the 6:1 he used due to friction.
There are several purchase systems that work and he advised to keep an eye
open for innovations. As for the technique to pull on the vang, use your body
weight and keep the arm straight, rather than trying to do it with your
arm. Put
marks on the vang so that you can set it . This is very useful when
setting the sail
for the reach/run when approaching the windward mark. Off the wind, it is
better to err on the loose side with the vang tension. An overtight vang creates a
tight leech and an underpowered sail. A vang that is too loose results
in a sail with too much twist and will have to be overtrimmed to prevent it from
luffing. Its leech is fluffy and spills air. A correct vang tension will
create a "bouncy" leech. Changing
gears consists mainly in adjusting the vang . Steve changes its vang setting
about 15 times in a beat of a major regatta course. To do this it is important
to have the vang line handy when needed. Make sure it is the right length,
it has a double line bowline (to be easy on your hand) and is on the windward
side. Throw the vang line to leeward before every tack. It will first fall in
the water, but the water itself will put it on the deck. Remember
to keep the vang looser than normal for the start (see section on starting). Steve
always puts some cunningham. Besides the well known effect of the
cunningham (moving the draft forward), it also "cleans up" the sail,
i.e . removes
the wrinkles referred in the paragraphs above. It is important to tension
the cunningham before the vang so that the vertical tension on the luff transfers
all the way to the top of the sail. If the mast is bent, friction will
prevent this. Take this into account when setting the sail before the leeward
mark rounding. The
cunningham should be loose when sailing off the wind. Steve
(180 lbs) admits that there are other "schools of thought" with regard
to the
cunningham. For example, Mark Brink (200 lbs) never puts his on unless
he is
overpowered. Steve
also recommends the typical outhaul system with purchase and the
outhaul line looping around the mast. Make the front
purchase knot very small so that friction will keep the line taut and prevent
it from falling.
NOTES ON LASER BOAT PREPARATION
AND BULLET PROOFING The
purpose of this section is twofold: 1
be able to tune better/go faster; 2
avoid breakdowns. a)
Boom and traveler: First,
note that purchase systems in the traveler are not legal. In fact they are not
necessary. A high "natural purchase" can be obtained by making the loop in the
traveler line as small as possible. There
is a design flaw in the boom and traveler system. The aft block of the boom is
on top of the traveler only when the boom is in the middle. This makes it
difficult for the traveler blocks to get all the way to leeward because
they are are
forced to stay over the traveler (which forms a straight line) while being
pulled by the aft boom block, which describes an arc centered at the
mast. This can
be cured by bringing the traveler under the path of the boom block at its two
ends, instead of doing it at a single point in the middle. (**
Technically speaking, you don't want the line defined by the traveler
to be tangent
to the arc that the boom block describes, instead you want it to be a secant to
this arc, i.e intersecting at two points . In absence of other forces, the
traveler blocks tend to go to these points when the sheet is taut **). This
can be accomplished by doing two things: 1
- Make the loop with the traveler line so that the traveler blocks are
ahead of the
fairleads, and the bowline knot is aft (when there is no traveler
tension). This is
the opposite of what is normally done. 2
- Move the eyestrap of the boom block aft (class rules allow this,
within certain
margins). See section on thru-bolting later. The
boom plastic cap by the gooseneck wears out very fast. Don't try to
take it out,
instead (*** help!!!, I missed this***). b) Thru-bolting:
All fittings in the spars are mounted with rivets at the factory.
These work well when they have to stand shear (force tangent to the surface
they are applied to), but they fail easily when they have to hold to tension
(force perpendicular to the surface). It is very important to thru bolt the
latter type, which includes the eyestraps for the boom blocks, vang (** check
nomenclature **) and the gooseneck. Except for the aft bolt of the aft boom
block, none of the bolts is supposed to go all the way thru the spar. To
put these bolts remove one of the caps of the spar to be fixed. Get a
long piece of
thread and at one end tie something heavy that will fit thru the hole where the
bolt has to go. Put the spar vertical, pass the thread thru the hole and use
the weight at the end to bring it all the way to the edge of the spar. Tape the
bolt to the end and pull it to the hole and pass its thread thru the hole.
Then get a regular bolt (not a lock bolt) and thread it in. To tighten it use a
vice script to hold the bolt (it has to be longer than strictly needed), then saw
the extra length of thread. If you were to use a lock bolt, you would never be
able to remove it after sawing the screw. As
mentioned above, the aft bolt of the aft boom block eyestrap goes all
the way thru the
boom, thru the aft hole of the boom block eyestrap in the lower part of the boom
and thru the front hole of the outhaul fairlead at the top of the boom. Always
use stainless steel nuts, bolts and rivets; and always use an inhibitor
sold
at marine stores) to prevent electrolysis. The
gooseneck only needs one of the rivets to be substituted by a bolt on
each side.
Replace the top two rivets by bolts in the vang eyestrap. Also,
thru-bolt all blocks. The top traveler block is difficult to do because the pin
rotates when trying to drill it out. The
hiking strap also needs to be thru-bolted. If you want, substitute only
one of the
screws by a bolt (the one closer to the inspection port is easier to replace).
Make sure you impregnate the thread with silicone sealant before putting
it in. c) Tricks to keep the board from
coming up:
1 - replace the rubber holder often (they
are cheap, buy a bunch at a time)
2 - Apply a line of silicone sealant around
the centerboard trunk (doesn't matter where in the trunk), so that the
centerboard will stick to it. Don't overdo it. Changing the shape of the
centerboard trunk is illegal. d) How to deal with bent top
sections if you can't afford a new one?
Always rig your boat
with the tip of the top section leaning forward. The action of the sail
bending the mast (with the mainsheet and vang acting as described in the section
about tuning) will straighten it in most cases. If it doesn't, take the caps off
the tips and reverse them, so that the top section will be used upside down from
then on. e) Bottom sections:
they can also be inverted following the procedure above. You might
want to do that if the holes for the vang eyestrap have been redrilled
several times and are no longer usable. Fill the old holes by popping rivets in
them. It is illegal to keep them open (this is to prevent people from playing
with the mast stiffness by drilling holes in them). Also
make sure that the gooseneck pin is tight. f) Tiller and rudder:
It is important to minimize friction in the tiller to be able to
feel the helm. Avoid having the rudder tie down rubbing on the stern. Also,
build a roller with PVC tubing to minimize the effect of traveler
friction. To do
this, get a PVC tube of inside diameter close to the tiller diameter,
cut two small
pieces so that you can put them fore and aft of the roller, attached to the
tiller to prevent the roller from sliding along it. It
is very important to set the rudder as low as possible (78 is the
maximum, as shown
in the ILCA rulebook). This is so important that Steve uses a bolt with an
hex head and tightens it hard so that the rudder gets locked in place. g) Blades: Blades will wrap if left under weight or in certain
positions under high heat
and humidity. The trunk of car with the blades under all the sailing gear is a
perfect example. Try to avoid leaving the blades it hot and humid places
and place them with the weight along the front edge of the blade. If a foil does
get wrapped, get it hot with a wet towel and an iron. You will have to be
patient and keep adding water to the towel (**check**). Once it is hot,
manipulate it gently with your fingers. Blades
also need to be faired to perform well, specially if they hum when going at high
speeds. Start by spraying the blade with paint of a different color that the
one of the blade (**any other requirements as to the type of paint??**) Then sand
it with a block and 280-220 sandpaper. The low spots will be easy to see
because they will keep the paint until they are fair. Once the
blade is fair, make the surface smooth by sanding it with a 400-600 paper
without using a block. Then paint it. Steve
likes to sharpen the trailing end of his blades. This makes them
fragile. It
is a good idea to mark the centerboard, just as you would do with
lines. h) Bailer: When
installing it, seal the edge with a line of silicone sealant either on
the bailer or on the hull). This will improve suction, and will make the
bailer work even at low speeds. In heavy
weather there is always the problem of kicking the bailer shut when you want it
permanently open. To prevent this, take the rubber off and jam it under the
grabrail. i) Hiking strap:
Needs to be thru-bolted (see section on thru-bolting above). It
is important that the strap itself doesn't roll up. If you have a
standard strap,
have the seams reinforced (** or put extra seams?**) by a sailmaker or someone
with a heavy duty sawing machine. Padded straps are good, i.e. they don't roll up
but the padding is not necessary if you use hiking boots.
It is very important to have an adjustable hiking strap system. Several
systems work, but
Steve prefers the one that relies on the line pinching itself rather than on
friction. Make sure that
the strap itself is short enough to allow maximum adjustment range. Also,
use a piece of shock cord looped between the aft end of the strap and
the traveler
cleat to keep the strap high when you are not using it (such as in the middle of
a tack) and make it easy to slip your feet under when you need to hike. When
hiking, you have to lock your legs between the hiking strap and the
inner edge of
the copkit. The further out you hike, the harder it will be. j) Outhaul:
The typical outhaul system with purchase and the
outhaul line looping around the mast is
recommended. Make the front purchase knot very small so that friction
will keep the
line taut and prevent it from falling. k) Leaks:
It is very important to seal the boat. This will eliminate one variable
if you find yourself being slow on the race course. There are
several places where a boat can leak. The amount of water the boat takes can
give clue on where the leak is. If it leaks a lot, the leak is provably
in the centerboard trunk, the bailer hole or somewhere else under the
waterline. A small leak can be due to defects above the waterline:
inspection ports,
grabrails, (** mast step??**), etc. To
find a leak, place a small piece of tape under the vent hole in the
forward wall of
the cockpit. Put very soapy water over all possible leak spots and blow air into
the hull thru the drain hole. Bubbles will form at the leak spots. For
small leaks, you can blow with the mouth. Large leaks need the exhaust
of a vacuum
cleaner. Be careful not to blow too much air into the hull, since this can crack
the joint between the upper and lower hull sections. If you use a vacuum
cleaner, allow some air to escape in the path between the vacuum exhaust and the
drain hole.
Most of the leaks are straightforward to fix with silicone sealant. The
bailer hole and
mast step require special attention. l) Mast step reinforcement:
If the mast step has been leaking, it might be weak. Mast step
failure while sailing results in major damage, so don't overlook this point. To
hold the mast in place, there is a wooden piece on the lower hull
section. The mast
step tube in upper deck section comes onto this piece and is attached with an
adhesive paste. This paste degrades with water, and it will fail if the mast step
leaks for a period of time. If this happens, the mast will fall and will
break the deck. To
avoid this, cut two inspection ports at each side of the mast step and
chisel out the
adhesive material. Then replace it with fiberglass.
m) Cordage:
Use 1/4 Yale light for mainsheet, 3/16 Marlow pre-stretch for traveler,
vang and outhaul. Any smooth line will work for cunningham.
DRILL
DESCRIPTION AND COMMENTS MADE IN DE-BRIEFING SECTIONS *)
Find the line drill: The drill consisted in setting a very long line and having
people sail thru the middle of it and raise their hand once they were on the line. People got
the hang of it after a while. They started with the "on the line" landsight
and after a few times were raising their hand when their bodies were on the
line and the bows were over. This was solved by drifting down a couple of
boatlengths at the boat end, then getting a landsight and raising the
hand on it when
starting at the middle of the line. *)
Two- minute starts: This was a series of consecutive starts with a two
minute countdown
sequence. The starting whistle for a start was the two minute signal for the
next one. On pin
favored starts, make sure you get on the line (or very close to it) with enough
anticipation. It takes a long time to reach the line. On boat favored starts be
careful with your time-on distance. People
who on the final minute spent a lot of time in the verge of loosing control ,
i.e. they kept the bows very close to the wind and where most of the time
sculling to bring them down, ended up sidesliping more than those that kept them
slightly lower but alternated between sculling up and sculling down. *)
Reach start: In this drill we started on a reach, went to a jibe mark
and finished
upwind. Our goal was to round (legally) next to the mark, no matter what.
This might take a lot of thinking ahead, specially if there are many boats. Talk to
the other boats way ahead of the two boatlengths circle. You might be in a
position (being ahead and clear astern or having an inside overlap)
where an
acknowledgement of your situation by the other boat will lay the onus
on his her. If
nothing else it will prevent getting into a big mess and loosing many positions. Whenever
possible, try to think how tight the mainsheet has to be at the second reach and
try to come out of the jibe with the right amount of sheet tension. On a reach
don't go low unless you don't have boats immediately behind you. *)
Leeward start: we started downwind, rounded a leeward mark and finished
upwind. The goal
is the same as in the previous drill, but the consequences of rounding outside
are much more severe.In this
drill, slowing down the boat to give time to the boats inside to round is very
difficult. Thinking ahead is even more important than before. The course
was short and when the starboard end of the line was favored, it was difficult
to decide whether it was worth starting there and running the risk of getting
stuck outside of a pinwheel. *)
Jibing: It is
very important not to rush the jibe. Trim the sail in before the jibe. This
reduces the angle that one has to turn to get the sail across. Roll the boat to
the old windward and pull the sail across. Make sure that when you roll the boat
back up you have the sail full and trimmed in so that you can roll against
it". Don't bear off until you have built up some speed. Steve does the hand
exchange squadding down in the copckit in the middle of the roll. A photo example.
*
