Sail your 125 Faster
- Keep the boat flat at all times
- Keeping the boat flat is one of the biggest factors affecting boat speed. There are 2 factors at work here.
The first is that as the boat heels, the force generated by the sails becomes more downward and less forward. This
means that there is less forward force and more drag.
The drag comes from the sails pushing downwards combined with a crew that is hiking/trapezing out further (but
really moving upwards rather than outwards), this pushes the side of the hull deeper into the water, thereby creating
The second effect is that the more you heel, the less effect your centreboard has. As you heel the effective
length of your centreboard is shortened, and you will slip sideways more easily.
Therefore keep the boat flat at all times, EVEN IF THE SKIPPER HAS TO EASE THE MAINSHEET WHILE THE CREW
IS GETTING OUT ON WIRE
- Be near each other
- When the skipper and crew are close together, it reduces the moment of inertia of the boat (think of it as
rotational weight). This makes it much easier for the boat to lift its nose over waves, and then to dive down the
other side. It is much quicker to roll over the top of a wave, than to plough through it, and once at the top you
can accelerate down the other side.
- Let the boat sail itself
- Given that your boat has fairly neutral helm (see rigging tips),
the skipper should only be guiding the boat's direction, not controling it. Rudders work by acting as a brake on
one side of the boat, as such if you are putting a lot of force into controlling the rudder, then you are using
this brake a lot. Try to adjust your rig, and the way you sail the boat, so that the skipper barely need hold the
tiller at all.
- Don't point too high
- Given that your sails are set correctly, you should have the leech ribbon on your jib flowing. This will usually
be happening when your luff telltales are all flowing (both windward and leeward sides of the sail). The reason
for this is that the jib is used to speed the airflow around the outside of the main, thereby generating more power
from the main (remember the sails are wings generating lift). When the leech ribbon on the jib is flowing, you
are getting maximum airflow over the leeward side of the main, giving you maximum power.
- Don't oversheet the main
- Given that you're not pointing too high, now you need to be careful not to oversheet the main. The tighter
the mainsheet, the more the force from the sails is pulling sideways, and the less it is pulling forwards. You
still need the boom near the centre of the boat, but if it is actually in the centre of the boat, you've probably
got it oversheeted. Watch the leech ribbons, they should be flowing at least half the time. You'll need to experiment
and get a feel for what is correct, so that you don't have to watch the sail all the time.
- Keep your weight forward
- Usually when going upwind the boat will not be planing, therefore one of the things affecting boatspeed is
waterline length, the longer your waterline length, the faster you will go (given all else is equal), and the less
you will slip sideways. Sitting forward will also reduce the drag of the boat. Think if you were sitting on the
transom how the boat would sail, it would be like pushing a brick wall through the water, as you move forward,
it becomes more and more like sliding over the top of the water.
There is obviously a limit, which will depend on the crew's total weight, and the conditions you're sailing
in. As a guide in 12 knots the skipper should be straddling the thwart, with the crew just forward of them. Move
forward a bit as the wind gets lighter, back a bit if the bow is taking water over it or the wind is strong.
- Up in the puffs, down in the lulls
- When a gust hits (with no change in wind direction), it will enable you to point higher, without loss of boat
speed. This is because a gust always moves the apparent wind (the wind that actually drives the boat) closer to
the true wind. The apparent wind is always further forward of a moving boat than the true wind, so a gust (without
change of direction) will always lift the boat, likewise a lull moves the apparent wind further forward, thereby
knocking the boat (but you shouldn't tack, as it's not a true knock).
- In planing conditions
- Off in the puffs, up in the lulls
- When reaching in planing conditions, the reaction to a gust is the reverse of that when going upwind. A gust
still moves the apparent wind closer to the true wind, but on a reach that will induce more heel in the boat, to
counter this you should bear off more to reduce the heel. When the wind lulls, bear up to keep your speed up and
the crew on wire.
- Keep your weight back
- On a reach the wind is a lot more behind you than when beating, this means that the main and jib are pushing
the nose of the boat down (if set correctly the spinnaker should be lifting a little), not only this, but you are
trying to get and keep the boat planing. To do this you should be keeping your weight back in the boat.
Again, not too far back, or you'll just be sailing with the nose up, rather than planing. As a rough guide the
crew should be roughly in line with the thwart, the skipper just aft of them. Move back as the wind and/or waves
increase, and forward in the lulls to keep the boat planing.
- In sub planing conditions
- Don't change direction for puffs, lulls or small knocks and lifts
- The shortest course is a straight line. On a reach in subplaning conditions, this is the course to take, it
doesn't matter if the wind changes direction or speed. The exceptions to this are if a change in wind starts you
planing, or changes a reach to a beat or run. Also you might still change course to catch waves, to avoid wind
shadows from your competitors or to catch a gust earlier and stay in it longer.
- Keep your weight forward
- Like when beating, your speed when not planing is affected by your waterline length. As such, you should try
to keep your weight forward (similar positions to when beating).
- Treat the run as a series of broad reaches
- When on a dead run, your speed can be no faster than that of the wind. As such you should perform a run as
a series of broad reaches. The speed advantage of being on a reach should make up for the extra distance covered.
As a guide, set your jib wide and sail so that it just sets.
Other downwind advice
- Catching waves
- Catching waves makes an enormous amount of difference to your average speed. You should be trying to catch
every wave that you can. To catch a wave start with your weight forward in the boat and as much speed as you can
get. When the wave starts to come underneath you, turn the boat so it is facing down the wave to get maximum acceleration,
and pump the sails (keeping in mind the rules on pumping). As soon as you feel you are on the wave, bring your weight back in the boat and take
a course more across the wave to get maximum speed, if you feel the wave slipping underneath you, face back down
it to try and stay on it.
For more information on boatspeed, see Racing Basics
For a good collection of racing information see The
This file may be freely copied and distributed, provided the information within
it is not altered, and due credit is given to the National Australian 125 Association.
It's URL is http://www.125assoc.com