Marking Things On The Boat
Book Extract
A brilliant sailor like Paul Elvstrom, who won five gold medals in a row, would never mark anything because he preferred to ‘feel’ the boat. But for us mortals, marking settings and putting on reference marks helps trimming, gives a guide to speed, enables fast settings to be repeated and may prevent arguments! Because you’ll always want to change the marks once they are there, take out black, red and blue pens. For dark sheets use whipping twine wrapped round three times and sewn through the rope. Most control lines have a range of settings, but halyards are a special case. They only have one position – up! Mark the jib halyard to show it’s up and that it hasn’t slipped. Use a wire main halyard with a hook rack. Set it so the head of the sail is at the black band. Check before the start of each race that it’s in position. The spinnaker halyard mark is 5 cm long because it doesn’t matter if it’s right up or down a little, and it may sometimes be an advantage to have a gap between the head and the mast. This mark is really useful – you can put your head down and pull like crazy until the mark lines up, then go straight into trimming the sail. All other sheets and control lines have a range of settings, depending on the wind. You should be adjusting them all the time. Note that changing one affects all the others – though it doesn’t mean you have to adjust them too. For example, raising the jib tack alters the sheeting angle and also tightens the jibsheet (which may or may not be what you want). Just be aware of what is going on.
THE JIB
Mark the jibsheet as a reference. It will hardly ever be lined up because there is an infinite range of sheet tensions needed. But it is very useful to be able to say something like ‘Pull the sheet in until the mark is 2.5 cm (1 in) from the fairlead’. I suggest you pull in the jibsheet hard, then let it off 5 cm (2 in) and mark it at that point. Then take the sheets off, lay them parallel and mark the other one at exactly the same position so they are symmetrical. Once you’re sailing you will be constantly adjusting the jibsheet – in in a gust, out in a lull. But to begin with, cleat it to give the helm a chance to get ‘in the groove’. The jib fairlead is restricted by the class rules. Mount it on the thwart with a 25 mm riser. The jib tack line needs a mark on the rope and a scale on the foredeck.
THE MAINSAIL
As with the jibsheet, put a mark on the mainsheet to act as a guide. Put three marks on the downhaul (on other boats this is called the cunningham). These are your approximate settings for light, medium and strong winds. Of course, when the downhaul is tight it opens up the top of the leech and depowers the sail. The clew outhaul has two marks, one for beating and one for running. Reaching settings are in between. Make the upwind mark so there is a 10 cm (4 in) gap between the foot of the sail and the boom, and the downwind mark so there is a 15 cm (6 in) gap. Note that on a light wind run, the outhaul may be very tight. The kicking strap (vang) is the main control on most boats and it’s vital to know how much tension you have on it. Assuming you have a cascade system, make a mark on the fixed line and view a block moving past it.
THE SPINNAKER
Mark the spinnaker sheet for close reaching. Set the pole just off the forestay and mark the guy where it enters the cleat. Repeat on the other side. Put a mark on the jib luff to show a good pole height.
THE DAGGERBOARD
With the boat on its trolley, carefully put in the daggerboard. The pads will hold it in the fully ‘up’ position – mark this on the board. Then take it out and put a mark at the halfway point.
RIGGING
MAST RAKE
To measure mast rake with a Burmuda rig hoist the end of a tape measure to the top of the mast. Pull it tight down to the bottom black band (by the boom). Adjust the halyard until the top of the black band measures 4200 mm (13 ft 9 in). This ensures you have the tape measure hoisted to the standard position. Now swing the tape measure aft and measure to the top of the centre of the transom 5100 mm (16 ft 9 in) is a good starting rake. For the gaff rig, measure the rake from the aft face of the mast at the point where the main halyard enters, to the top aft edge of the transon on the centre line. This should be 355 mm (11 ft 8”).
Measuring the mast rake – Burmuda rig
JIB HEIGHT
When setting up the jib it is possible to change the height of the tack. Moving the tack up or down the forestay changes the angle of the jibsheet. This, in turn, opens and closes the leech because the jibsheet position is fixed in the boat. The higher up the forestay the more closed the leech will be when sheeted in. Most sails will be designed to have a sheeting angle of approximately forty-five degrees. This is a good angle to start at.
RIG TENSION
You measure rig tension with the boat on the trolley and the sails down. Take your Loos gauge (or similar) and clip it onto a shroud at nose height. Pull the string and read the tension. About 15 is right as a general setting. Less in light winds and more in strong winds, though on a Mirror, without spreaders, trying to increase rig tension only bends the mast. Note that the gauges all read slightly differently, so if you want to compare your rig to someone else’s you need to use the same gauge on each.
In summary, tuning is really a question of adjusting the mast rake and shroud tension and moving the jib up and down at the tack. Simple really. Get that boat sorted, then go out and win!
© Not to be reproduced without written permission from Fernhurst Books Limited.
The Mirror Book is written by Peter Aitken & Tim Davison. Peter Aitken was the UK National Mirror Coach and has also coached sailors to win the Cadet and 420 World Championships. Tim Davison has been Laser (Masters) European and National Champion and British Moth National Champion.