Steering a Lightning through a heavy chop is not an easy task. The “resonation” made by the bow slamming the waves when it isn’t “done right” is the best tattletale there is of improper tune and steering. While it isn’t possible to miss them all, there are some things that can be done, sail trim, tuning, and steering wise to help make the job a little bit easier.
The natural inclination when sailing through chop is to power the boat up as much as possible. While obviously the boat does need extra punch, how that punch is directed is most important. The first indication that the boat is not set up just right and that there is maybe too much power for the wind is the feel at the helm. If there is too much weather helm (the boat wants to round up into the wind) the boat will be very difficult to steer through the chop. Excessive weather helm means the tiller will be pulled to windward of centerline and the rudder will be literally dragged through the water.
Usually it is not too little backstay or too much mainsheet that creates the problem of excessive weather helm. Most Lightning sailors are comfortable with setting the mainsheet so the upper batten is angled outboard slightly from parallel to the boom. Most also just pull the backstay until the slop is just barely removed (unless it is blowing really hard). However, it is the traveler position that usually unbalances the boat. Normally we think that we want to pull the traveler up to a point where the boom is close to centerline since the mainsheet is eased and the upper batten is open. However, the bottom of the main is still powerful and the lower leech is hooked in relation to the centerline of the boat. In chop it is not unusual in a 8-10 mph breeze for the traveler to be down to leeward perhaps as much as 6”. Actually, the true gauge will be the feel on the helm. The helm must be nearly balanced so the boat can almost steer itself straight upwind all by itself. In flat spots, the traveler can be pulled back near centerline and the mainsheet trimmed to the batten parallel to the boom position. However, as soon as the boat enters waves again, traveler must go down and the sheet eased.
It is also natural to want to heel the boat a great deal because it seems to put a more ”V’ed” hull shape to enter the waves. While this may be true, a boat sailed with more heel develops more windward helm. Instead, try to keep the boat flatter, maintaining the weather chine no more than 3" to 6" out of the water. Many Lightning sailors sail with the chine just barely touching the water so that the boat is only heeled 10 degrees at the most. A boat that is balanced and sailing fast can still be steered to miss the biggest waves.
Steering around the waves should not be accomplished with only the tiller. The more the tiller is wiggled, the greater drag and the more the boat will slow down. Instead, ease the mainsheet (sometimes as much as a foot) to help the boat bear off and then trim it back in to help the boat head up. Be sure when trimming the main back in not to overdo it so the weather helm again won’t load up.
Be sure to adjust the jib also as the-boat heads up and bears off, but don’t overdo that either. If the jib is eased more than the ease of the main, the boat will not have the tendency to bear off and it will be much more difficult to "steer" through the waves. Unless it is extremely light, the jib should be eased out so the batten is angled close to the tip of the spreader and never trimmed inboard more than 1" to 1.5" inside the tip. In light winds, don’t be afraid to ease it out to as much as 2” outside the tip of the spreader.
Check that the extra life jackets, tools, water bottles, spinnaker poles, etc. are brought in from the ends of the boat and centered as close to the centerboard pin as possible. The crew weight too needs to be centered close with the skipper moving forward and the forward crew moving aft to help minimize the boat’s tendency to hobby horse through the waves.
Finally, be careful to avoid pinching at all costs. A boat that is going fast through the water will go up and over the waves much easier than one that is slow and loaded up with excessive weather helm.