Adjusting Genoa Leads
By default the genoa lead car position should be placed in the projection of the line form by splitting the luff in half (mid luff) and its projection through the clew of the sail.
If that is the case then why do we have to adjust the genoa lead car (fore-aft track)?
Assuming we are close haul sailing:
a. Let's talk about powering up: You were sailing in a decent breeze and it drops, you call to ease the genoa sheet and start footing. As soon as you let the genoa sheet out the leech will twist in the upper section and your boat will start losing performance. Also, the sail will go up before it pushes forward. Moving the lead forward to keep the leech at the same distance from the spreader (upper spreader) as the foot is from the shrouds, this will keep the air flow translating into more speed. Also, if you need to punch through choppy conditions, move the lead forward, lead the genoa sheet out and foot the boat for extra power.
b.The breeze is up, the boat is heeling and there's no chance to peel the genoa for a smaller jib. Moving the lead back will flatten the bottom section of the sail while twisting the upper section (spilling air), therefore, depowering the sail plan. It is easy to see when the lead is aft because the foot will touch the chainplates before the leech touches the upper spreader.
Since modern sailcloth materials do not stretch, the only chance to twist or power up your genoa is by adjusting the genoa lead car, forward for power, back to de-power. Under ideal conditions, return to the default setting.
Please do not confuse this with "baberhauling" your genoa or jib.
Now, time to reach:
As you start easing out, you will need to move the lead forward until the sail become too round on the foot, then it becomes time to "barberhaul" the genoa (related article coming soon). If you leave your lead back while reaching, the sail will "float" not providing any power from the upper section. While reaching (cruising) trim with the middle section telltales, not the bottom one, for proper trimming. All three sets of telltales should be flowing indicating proper genoa lead position. If the upper one is facing forward or not attached to the sail, move the lead forward. If that is the case for the bottom one, then move the lead back. But keep looking for the middle one to be properly trimmed.
Note: Genoa lead position does not affect your ability to point, just to power or depower your jib or genoa.
Note 2: The closer the distance between the clew and the genoa lead car, the better you will be able to control the leech tension. While the farther they are apart, the harder it is to control it as the sail/clew will bounce around on each wave.
Senior Sail Consultant