Weather Helm and Genoas

The concept of sail balance is pretty easy to grasp. Powering up the headsails will produce lee helm as it moves the Center of Effort (CE) forward. Powering up the mainsail will produce weather helm as it moves the CE aft. When the forces of the main and headsails equal each other, the CE will align with the Center of Lateral Resistance (CLR) and will sail straight.  

If you suffer from weather helm, all you need to do is add more headsail area and/or reduce mainsail area, as this will move the CE forward and reduce the weather helm felt by the captain. A genoa is a massive headsail which should give you plenty of leeward force and help balance out the yacht, but this may not be the case. 

As you sail and feel weather helm, you might try reefing the main and letting out more of the genoa from the roller furler. Somehow, nothing seems to have changed! The weather helm is still present. Letting out more genoa doesn't seem to help any more either, as the problem continues to exist! 

Why would such a large headsail fail to balance out the sailplan? The answer is simple: a genoa is a jib that extends beyond the headsail triangle and continues aft of the mast. While the headsail is set forward of the mast, the portion that exists aft of the mast will move the CE aft. The larger the genoa, the more this effect increases.  

This is why you will see people beating to windward under genoa alone, with no mainsail, and they will be sailing along at a good pace! The large headsail, especially with genoas that are 150% or larger, will create enough weather helm by themselves that they are able to power your yacht to weather. Adding a mainsail to the combination only exasperates the situation, adding even more CE aft which will create even more weather helm. 

If you have a genoa and find your self struggling with weather helm, consider roller reefing your genoa before you try to reef your mainsail. Reefing your genoa will actually move the sail area forward and also move your CE forward which will help reduce weather helm and balance your sails. 

What is Sail Balance

A perfectly balanced yacht is a dream that most long for. The thought of setting the sails with the rudder straight and locking the helm as the yacht sails herself through the seas towards their intended destination.

Then reality comes when you set the sails and find that it keeps turning to windward and you end up dragging the rudder to leeward as you fight the forces and try to keep on course. If the winds build up too much, you will soon feel overpowered as your arms turn into spaghetti noodles with exhaustion and your yacht rounds up into the wind. 

The fight is over, and the forces of wind and balance have won! But why does this happen? 

Weather helm is caused by two forces: wind force and hydrodynamic force. The wind forces on the sails add up into what is referred to as the "Center of Effort" which is none other than the geometric center of each sail, and then the combination of each sails Center of Effort (also referred to as CE) to give you the yachts CE. 

The hydrodynamic forces are the same concept, being the geometric center of the underwater profile when viewed as a silhouette. This is called the "Center of Lateral Resistance" and is also referred to as the CLR. 

CE can be moved around by changing the sails that are flying and adjusting the trim of the sails, but CLR does not change.

Basically, you have two variables that control balance, one is fixed, the other is in your hands to control!  

If the CE is aft of the CLR, the yacht will want to turn to windward. This is the case if too much sail is being flown aft and not enough sail is being flown forward. 

If the CE is forward of the CLR, the opposite will occur and the yacht will want to turn downwind. This is the case when flying a giant spinnaker, as the large sail area forward will pull the yacht downwind and will not allow the yacht to travel upwind. 

Balance occurs when the CE and CLR are in the same position fore-aft. When this occurs, the yacht will sail straight with no desire to turn, requiring no input from the rudder to keep it on track. 

Sailing in a Gale

When we plan our ocean voyages, we all picture smooth sailing with fair winds and following seas. The truth is, most of your days will be in these conditions; some of your days will not. 

When we first noticed the clouds approaching us, we turned the VHF radio over to the WX channels to listen to the forecast. When we left, the winds were supposed to be from the North to North West the entire voyage! This is great as we were heading South and this would put us on a run to broad reach the whole way. Then the forecast was calling for a bit of a storm for two days, blowing 20-30 knots from the South. 

Maddie and I discussed our options: We could beat into the weather for two days under reduced sailplan, or we could heave to and relax for a few days, continuing our journey once the winds were in a more favorable direction. 

We chose to heave to. 

At first, the winds were just as predicted, 20-30 knots from the South, pushing us North at 0.5-1 knot. We rocked around as we slowly drifted through the water. In a 48 hour storm, our drift would only be 24 to 48 miles, easily recovered on our next day of good sailing. We made the choice to simply wait it out and ride the storm inside the cabin where we would be warm and dry while the boat hove to and looked after us. 

At nightfall on the first day, the winds began to build. They intensified from the 20-30 knots up to 30-37 knots. This doesn't sound like a huge change, but the power of this added wind caused the seas to rise up and we were glad to be hove to! The next day, the winds had climbed even further, holding at a steady 40-45 knots with gusts over 50 knots. The seas became huge towers that made our home bob up and down like a cork in a washing machine! 

This is when the situation changed. The winds were different from the forecast, blowing stronger and also blowing in a different direction! Instead of being blown North, we were being blown East. Normally, this would not be a problem, but for us it was! 

Our anchor had jumped out of the bow roller and had gnawed on the headstays deadeye. Dyneema is very strong, but its weakness is in chafe resistance. The anchor severely crippled our headstay, making it risky to fly any jib on that stay. If we lose our headstay, the mast will want to fall aft and present us with a whole new world of problems. 

Being 50 miles off the coast at this time, we decided that we needed to start limping our way back to shore to carry out repairs of our crippled headstay. This is where knowing how to sail in big seas and high winds pays dividends. 

The first thing you want to do is have the appropriate amount of sail flying. If it's blowing 40 knots with 30 foot seas, don't go full sail! You need to reef down for comfort and for safety. 

The mainsail should be reefed down as far as it can while still providing you drive to windward. Your headsail should be reefed down to balance out the sailplan and provide control to the helm so you can power through the seas. 

If you are sailing off the wind, a trysail would be a better fit instead of the mainsail for a few reasons. First, it spares the mainsail from any stress caused by the high winds. Second, it removes the boom from the equation which makes jibing safer and less stressful. Third, the sheets are run to the toe rail, making the risk of an accidental jibe much less likely. 

With the right amount of sail up, the boat will handle normally, just like if you were sailing along on a nice calm day! The difference between a calm day and your current day are obviously going to be the seas. Large waves present a few problems. They will cause your speed to fluctuate and they will rob your wind.

When you are in the trough of huge waves, they will actually steal your wind! You will notice this if you are flying your trysail, as its head is usually around the height of your spreaders. When the waves are taller than your spreaders, your sail will go limp in the trough as it has no wind. When you climb to the crest again, the wind will hit your sail with full fury! 

The other issue has to do with your speed, and your ability to make way to windward. Your keel depends on speed through the water to provide resistance to leeward. If you are not moving fast enough, you will begin to slide sideways and not move in the direction you are pointing or desiring. You may have to sail further off the wind than you would like simply to keep your speed as you ride up and down the waves. 

When climbing a wave, your speed will decrease drastically. As this happens, you want to fall off to help keep some of that speed and keep your keel working. As you fall down the wave, you will pick your speed back up and can point higher than you need to. Sailing with large seas is a constant give and take as you rise and fall, where you will fall off and then pinch on each wave you encounter. 

This can be very tiring after several hours, not to mention days, which is why we choose to simply heave to and wait for more favorable winds to return. If conditions demand that you sail though, this is the way to do it and practice is the only way to perfect the skill. 

Having a basic understanding of what is needed to make your yacht perform is critical as you will need to interpolate all your knowledge to get your yacht to move in a safe and desireable direction. 

Cruising to the Bahamas: Hove To

Heaving to is a tried and true storm survival method. Notice I say storm "survival" and not storm "comfort". That is because there is nothing comfortable about being in a storm!

The waves built to around 20 feet with a period of 8 seconds. This means that every 8 seconds involved us dropping 20 feet and then climbing back up 20 feet. Imagine being on a massive roller coaster for 3 days, and you don't have a special seat with a harness. Instead, you are trying to sleep on the roller coaster, walk around on the roller coaster, even go to the bathroom on the roller coaster!

Cabinets would open by accident and the contents would pour out. The best thing to do at this point was to shut the cabinet and not put whatever fell out back in because opening the cabinet to stow what fell would risk having everything else also fall out on the next wave.

The inside of the boat became a disaster as we were constantly tossed around. Maddie was too seasick to eat, and I didn't feel like eating since that involved getting tossed around the cabin like a rag doll.

While the slick did calm breaking waves down into rolling swell, it only worked on the waves that were approaching from the direction of the wind. Rogue waves which travel their own path do not come from the direction of the wind and are therefore able to sidestep the slick and slam right into us. One most notable of waves came at us diagonally and crashed into the starboard bow with a massive wall of water and the crest of the wave travelled over the boat, coming down on the port deck. It basically looked like a surfer in the green tube!

While we remained safe inside the boat, we did have some issues arise that precluded us from continuing our journey to the Bahamas. Our hatches are rather old and appear to have a few minor leaks. When it rains a simple towel will suffice to collect any water that seeps through the hatch. Three days of rain and breaking waves on the hatch meant that our bed became completely soaked in salt water. Not only was our bed wet, but there was no way it would dry anytime soon.

We also suffered some damage to the boat from the breaking waves and felt that it would behoove us to seek a safe harbor to carry out the repairs.

Trimming Your Sails on the Ocean

While tell tales will let you know how to trim your sail for peak performance, ignoring them for the sake of comfort may also be wise. Having poorly trimmed sails will cost you some speed, but the peace and tranquility it brings could be worth it to you.

When sailing downwind in light winds, the main steals a lot of air from the headsails. If you have the sheets on the headsails eased, these sails will lift with wind and then slat as you come down a swell. When the sail falls, so does the tension on the sheet. The sheet block will then fall onto the deck and make quite a bit of noise.

Being how the wave period in the Atlantic is around 8 seconds, this means that every 8 seconds you will hear a "TWANG!" on the deck. Do this for an entire day and you might go crazy!

In situations like this, you are faced with two options:

1. Either drop the headsail so it stops slating.
2. Over tighten the sheet to avoid it from going limp.

When you drop the sail, you lose all of that sail area entirely and unbalance your sail plan. This is far from ideal, especially on a broad reach, where you need the headsails to provide lee helm.

Over tightening the sheets will keep the noise from happening, but it will make your sails less efficient. This might cost you a fraction of a knot in light airs.

If you are deaf, or willing to put up with the noise for the small amount of speed gained, then by all means, trim based on the tell tales. If you prefer peace and comfort, then it would behoove you to over tighten the sheets and keep the peace inside the cabin.