Guide to Solo Trim & Tune
You should position your body in such a way to maximise waterline length. In normal conditions this will be against the thwart. In very light conditions, e.g. less than 3 knots, move weight forward of the thwart to maximise water length and leeward to minimise wetted area (Greenwood).
(Update Aug 2012 ) To maximise boat speed use the tiller/rudder as little as possible – it acts as a brake as well as a steering device. In addition to using your body position to keep the boat flat it can be used to heel the boat the boat which affect the boats direction:
- heel to windward – turn downwind away from the wind.
- heel to leeward – turn upwind towards the wind.
The black band on the boom is a fixed maximum length marker and the sail may not be set beyond this. In practice, many sails are not pulled out to the band but the depth of the sail is calibrated against the black band for one particular sail (Griffiths).
The correct setting for the outhaul is difficult to interpret from the guides found. The draft or depth in a sail is measured from measured from the mainsheet blocks (McGregor).
For normal conditions the outhaul should be set such that there is 100mm maximum depth in the foot of the sail (Kimmens, North) and the creases have gone (Greenwood). This might be achieved by easing the outhaul 1/4″ (Speed) from the black band.
In powered hiking conditions the outhaul should be progressively tightened from 100mm to 50mm depth (North) or 100mm (Kimmens) until it puts a crease in the foot (Greenwood). This may be achieved by setting the outhaul to the black band (Speed).
Alternatively, if you follow the Rooster guide, keep it quite lose to generate power down low – leaving around 120mm depth in the sail. Increase outhaul tension to reduce the draft to 80/100mm in heavier conditions (McGregor).
Set the boom so it is inline with the inside edge of the side tank. As wind strengthens let the boom further out up to a maximum 250mm (over-powered) past the outside edge of the side tank (Kimmens, North). maximum 150/200mm (Griffiths). probably via the traveller?
In very light conditions, e.g. less than 3 knots, it may help to ease the boom slightly up to 30cm outside the corner of the transom. Sheeting in too much will stall the boat and its better to keep the boat moving and sheet in slightly once you have speed (Greenwood, Griffiths).
- Under-powered / Drifting – centreline to 50mm
- Under normal and hiking conditions – set at between 50mm and 100/150mm from the centre.
- Over-powered – increase up to 380mm as wind strength increases.
Kicker (Vang) Tension
In winds below ‘over-powered’ the kicker is used to ensure correct sail curvature. The kicker should be adjusted to allow the top leech tell tale to stream 80% of the time, flicking behind occasionally (Speed).
Once over-powered it can be tensioned progressively to de-power the rig by bending the mast and flattening the sail (Kimmens). Adjust the kicker to hold the boom parallel to the deck when you let the main (and traveller?) out (Greenwood). This approach helps retain sail shape when working the sail in the gusts (Griffiths).
If the boat feels choked or the wind drops then ease sheet and kicker tension (Griffiths). Chocking would be an indication that air is not flowing freely over the leech hooked leech?
The Cunningham is used to position the area of maximum draft (North4) which has the effect of de-powering the sail. As you increase Cunningham, tension in the luff increases, which promotes mast bend and brings the maximum draft of the sail forward. This also has the effect of opening the Leech reducing the drag in the upper portion of the sail (McGregor, Griffiths).
Used for de-powering the sail – in anything but hiking and over-powered conditions it can be off. When setting the Cunningham either: aim for max draft at 45% (Greenwood) or watch the top two battens and straighten them (McGregor).
Use a fraction in light conditions to stretch the luff to the desired length and remove creases when there is no pin in the tack (Griffiths).
In light conditions the board should be fully down so that it is raked forwards and the trailing edge is vertical (Speed). Alternatively, it should be positioned so the leading edge (LE) is vertical (Kimmens, North, McGregor).
Under normal conditions and as you start to hike it should be positioned so the leading edge is vertical (Speed, Kimmens). Or between trailing edge vertical (Greenwood) to 40mm further raised (North).
A slight amount of weather helm might be advantageous (Griffiths).
As wind conditions continue to increase raise the board enough to balance the helm. This could be between 40mm and 100mm from the trailing edge being vertical (North). In hiking and overpowered conditions if weather helm is experienced then it can be raised further (Speed).